Mining & TownsMining & Towns
South Australian Opal Towns & Fields
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Coober Pedy - 'Opal Capital of the World'
Coober Pedy – ‘Kupa Piti’ is an Aboriginal name meaning ‘White Man in a Hole’ in the language of the Kokatha people the traditional owners of the area. It was selected from four proposed names by a newly formed progress committee in June 1920.
'Coober', as it is affectionately referred to, by its 3500 or so inhabitants, is also known as the 'Opal Capital of the World'.
The Coober Pedy Opal fields contain the largest concentration of opal bearing ground in the world. Known for yielding big ‘runs’or patches of full colour ‘seam’ Opal, Coober Pedy has been the single greatest producer by quantity over the last century and was instrumental in making Light Opal (milky,white,grey & crystal) the platform of the Opal industry, in terms of market availability and recognition. 
Discovered in 1914 by Willie Hutchison the youngest member of a gold prospecting party which was desperately looking for water at the time. The 14 year old had disobeyed orders and strayed from camp to search for water in the surrounding foothills. When he finally returned after dark, although exhausted he wore a huge grin on his face and his eyes were brightly lit. Willie had not only located a waterhole, he also had a sugar bag full of Opal to show his much relieved father and crew.
Blower & Elevator extracts dirt from underground
Willie Hutchison
"Coober Pedy suffered during the Depression years when opal prices bottomed out. The discovery of the Eight Mile field in 1945 by Toddy Bryant, an Aboriginal woman, caused a great sensation. Her discovery of Opal within 20 centimetres of the surface was a turning point in the history of the field and went a long way towards establishing Coober Pedy's future prosperity." Len Cram
The desert landscape around Coober Pedy is extremely barren and the climate dry and unforgiving, 45C in summer and as cool as 4C in winter. The mesas and mogul hills are not only prospective for Opal they have provided low cost, temperate dugout living since the ‘diggers’ returned from the trenches of France in 1918. The exceptional stability of the region’s ancient sandstones makes tunnelling and the excavation of safe and adequate underground homes highly practicable. The temperature in most dugouts only varies about 5C all year round with temperatures inside being from 21C to 26C.
Interesting attractions in Coober Pedy include the mines, the underground churches, the local golf course which is completely free of grass and the ‘Breakaways’ which resemble a mini Grand Canyon.
To complete the outback odyssey and discover the heart of Australia and Opal country visit the Opal Capital of the World where Umoona Mine & Museum is a must see attraction! If you are lucky and speck some good colour you can stay at the Desert Cave, a 5-Star underground hotel!
Underground at Umoona Mine & Museum |
The  Postman's Place |
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Major working areas and famous mines include: German Gully, Black Flag and Benitos Folly South-East of town, Olympic and Southern Cross to the West-South-West. Zorba, Larkins Folly, Hellenic Hill and Russos Folly (15km) East of town. Hans Peak, 8 Mile, 10 Mile, Greek Gully, 14 Mile, 17 Mile and Shell Patch (35km) moving North-West of town in that order. Map of the Coober Pedy Opal Fields |
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Andamooka
Andamooka – Opal was discovered here in 1930 by tank sinkers Roy Shepard and Tim Brooks. Nearby Andamooka station was named in 1858 by John McDouall Stuart, after an Aboriginal word meaning 'large waterhole' which refers to Lake Torrens 20 km away.
The township of Andamooka is located 593 km north of
Andamooka crystal is still regarded by many as being the finest quality ever found. Opal occurs here in a variety of forms including gem crystal, black or ‘smokey’ crystal, jelly ‘blobs’, matrix, painted ladies and Opalised fossils including dinosaur bones.
The climate is arid, with daytime temperatures in summer (December to Febuary) regularly topping 40 C (104 F) and night temperatures in winter often dropping to zero (32 F) or below. Annual rainfall is extremely low, the average is just 160 mm per year.
Local tours include inspections of working mines, the historical cottages and magnificent Lake Torrens - the longest salt lake in the southern hemisphere.
Mintabie
Mintabie – although discovered in the 1920's by a well-sinker named Larry O'Toole, it was not until the mid 1970’s that extensive mining began here.
Red sand dunes covered vast amounts of Opal bearing sandstone much of which has been excavated almost exclusively by open-cutting 50mx50m claims to a depth of 20 meters and as far down as 40 meters. During the 1980’s Mintabie was the major source of crystal opal and produced excellent semi-black opal.
The opal from there has a reputation for being harder than most, which perhaps bears some correlation to the fact it is found in Ordovician (500 to 440 m.y.a.) rocks, much older than the Cretaceous (144-65m.y.a.) rocks which host most of Australia‘s deposits.
As far back as the First World War, Aborigines sold black opal at Coober Pedy which most likely came from Mintabie - 254 km to the northwest.
In October 1981, the Pitjantjatjara Land Rights Act came into force and Mintabie township & opal fields are now part of a large area of freehold Aboriginal land.
The population peaked at around 1,500 residents in 1988, but has declined steadily to approximately 250 today.Lambina
Lambina - Although first discovered in the late 1920's going into the depression years, very little work was done here until the late 1980's when some good finds were made at the Seven Waterholes diggings.
Good strikes of high quality stones in 1996 caused a rush to the field which is 100 km northeast of Mintabie on the eastern side of the Stuart Highway. Some 300 claims were pegged, however, before many of these could be processed, the Wik native title decision halted any new mining. In December 1997, miners were informed that a native title claim would be lodged over the greater Mintabie area encompassing Lambina. Since then negotiations between miners and native title holders have enabled mining to continue.
Lambina produced most of the South Australian White Opal product in the last decade of the millennium, the population has fluctuated from 200 down to around 10 today.
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Sources & Image Credits: ABSALOM'S OUTBACK, John Mabey, 1981. (Andamooka) Andamooka Opal, Peter Taubers (photo of rough crystal opal) BEAUTIFUL OPALS - AUSTRALIAS NATIONAL GEM - SPECIAL 2000 COMMEMORATIVE EDITION, Len Cram, 1999. COOBER PEDY, 65 YEARS YOUNG 1915-1980, Kerry E. Medway, 1981. DIGGING AROUND COOBER PEDY, Anne Johnson, 2006. Opaline, Photo collection Umoona Mine & Opal Museum, (colour photo of dugout interior) |
Queensland Opal Towns & Fields
Home of Boulder Opal
The Queensland Opal fields are spread over a belt 300-400km wide with a 1000km strike. Trending in a north-westerly direction from the
Seemingly untouched by man since the beginning of time, the vast, rugged landscape of the western region of the State has a rich history. More than 25 Aboriginal tribes roamed the country before the arrival of the pioneer pastoralists and Opal miners in the mid to late 1800's. Today huge sheep and cattle stations, mineral deposits, oil and gas fields contrast with the lifestyle of the nomadic Opal miner.
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 Lark Quarry dinosaur stampede |
Winton Precious Australian Opal was first found in Queensland where it occurs over of an area in excess of 100,000 square kilometres, in a multitude of forms and varieties. Making Southwest Queensland the greatest region of Opalisation in the world and the most prospective in the new millennium.
Lady Brassey in her book "The Last Voyage, to India & Australia, in the 'Sunbeam'" mentions that a piece of Opal was found by the overseer at Blackall Station on Listowel Downs, in 1869.
The beautiful fragment stood on the mantelpiece for several years before it was thought to be of any value, but at the time of the greatest mining fever attention was attracted to the specimen, and it was sent to a mineralogist, who pronounced it to be valuable Opal.
The Opal encrusted ironstone boulders discovered on the jump ups of the Barcoo district by early miners Berkelman and Lambert attracted great interest at the Queensland Annexe of the London International Gem Exhibition in 1873 and became known internationally as 'Barcoo Opal'. Following the discovery of further deposits hundreds of kilometres to the north near Kynuna entrepreneur Herbert Bond infamously formed a syndicate with the intention of marketing Queensland Boulder Opal to the world.
However, by the end of the 1870s, pioneer miner Joe Bridel had discovered a new form of precious Opal at Stoney Creek in the Kyabra Hills that lie north-west of Quilpie and to the south of Windorah. It was the solid seams, 'pipes' and nodules of precious Opal from this sandstone Opal that the pioneering Opal marketeer Tullie Cornthwaite Wollaston took to London in 1890 which was familiar yet superior in quality to any Opal the world had known hitherto and helped initiate the Australian Opal industry.
Today Queensland's Opal miners are above all in search of Boulder Opal, this 'heavenly marriage of ironstone and Opal' is widely regarded as one of the planet's most stirringly beautiful gemstones, particularly amongst the cognescenti.
Despite an apparent abudance of the resource in Queensland, Boulder Opal constitutes only a minor percentage of total Australian Opal production. The 'tyranny of distance' and the technical difficulty in the economic extraction and cutting of this most brilliant of gemstones are challenges which remain to be addressed as we celebrate 140 years of the Gem's first recorded discovery.
Winton – Northern Capital of Qld Opal Fields
The Winton Mining Area encompasses a vast region of intermittent Opalisation, famous for patches of brilliant black boulder Opal pancakes. Also home to ‘Lark Quarry’ - a fossilised dinosaur stampede, which showcases three different species’ footprints. Luckily discovered by an Opal prospector and now preserved as a major tourist attraction.
Opalton –124 km south of Winton, was discovered in 1887 by George Cragg, a 17 year old stockman on Warrambool Downs. Almost a decade passed before the commencement of mining on this field which proved to contain the highest concentration of Opal in Queensland.Today, a population of less than 20 inhabit what is a designated fossicking reserve, host to the most extensive Opal workings in Queensland, where once a township of nearly 600 people flourished.
The field includes numerous historical mines; Brilliant, Little Wonder, Bald Knob, Snake Jump, Conways, Dragon Fly, Kinder....
The largest piece of gem Opal ever recorded in the world was found at Opalton in 1899 by Dick Shillington and his mate Greenwood. It was 11ft long, as thick as a man’s thigh and took four men to carry it.
Working the Gem, an Opal cutter at Opalton in 1901 (pictured) has rigged up an old treadle sewing machine. Others used bicycles, designing innovative hand or foot operated cutting and polishing wheels.
Feelin Lucky Mate? Try your luck 'noodling' in the Opalton fossicking reserve!
Why not stay in a cabin or your own caravan, for more details contact the Opalton Outpost.
Jundah - Field (396 S of Winton) includes Jundah, Lina Glen, Opalville and Hayfield mines, and Stonehenge - Evengy Station to the south-west. The area is renowned for red coloured Opal in large sandy boulders and manganese Black Opal pipes.
The Black Mine was
Kynuna - Northern-most of the Queensland Opal fields (200 NW of Winton), the main field was discovered in 1894 and lies 40 km south of Kynuna township off the Landsborough Highway.
This vast area of potential Opalisation has been worked very little and is perhaps the deepest Opal profile in Queensland. The Opal country is dominated by sandstone mesas in areas which are highly elevated (320m ASL) suggesting up to 35m to the bottom level. The prospective areas thereabouts are west of the main Kynuna field and south toward Dagworth Station.
Middleton - Numerous Mines surround the Middleton Pub (169 km W of Winton) on Woodstock, Chiltern Hills, Franklin and Brighton Stations.
Windorah - Mt. Windsor to the west of Jundah. Palparrara and Curren to the south west.
Quilpie – 'Gateway to the Opal Fields'
In 1871 the first Opal lease in Australia was registered south of Quilpie. Very little work was carried out on the 360 acre lease other than the sinking a couple of shallow shafts, and the lease was abandoned after several seasons. Twenty years later, the discovery of Duck Creek further south brought renewed interest in the area, the lease was re-pegged and named Pride of the Hills.
Toompine - The Paroo Fields, as they are known, lie east and south-east of Toompine Pub (77km S of Quilpie); Including the famous Pride of the Hills, Lushingtons, Coparella, Sheep Station Creek, Emu Creek and Duck Creek.
Duck Creek is a small (≤1km²) gem Crystal Opal field (85km N of Yowah) discovered in 1891. Renowned for seam Opal of the highest quality, possesed of a brilliance surpassing that of almost all other crystal Opal on the Queensland fields.
Quilpie - West and north-west of Quilpie; The vast Quilpie Mining Area is home to several of the most productive Opal mines in history, the famously prolific Hayricks, Bull Creek and Pinkilla Mines are still operating today. The region is noted for producing considerable volumes of large boulders. These contain predominantly Light Boulder Opal which often runs into smaller amounts of Black Boulder Opal.
Bulgroo - Further north of Quilpie field in the
Yaraka - This field encompasses the mines on and west of the
Eromanga - "Farthest Town from the Sea" but just a hop and a skip to the Scotchman and some 'bloody ripper', 'you beaut' Opals! Also the namesake of the Eromanga Sea, the great inland Sea, that once covered much of the forming continent and the outline of which hosts the vast Boulder Opal fields.
Numerous discoveries were made in the area from the mid 1870's and the miners brought Cobb & Co. to Windorah helping to establish Eromanga, essentially Australia's first Opal mining town, with two hotels and a police station. However due to the sparsity of the surrounding deposits Eromanga was eclipsed and the monicker taken by Whitecliffs in a little under two decades.
By 1878 over 200 men were combing the 'Kyabra' hills to the West and Keerongooloo Station to the NW and until the collapse of the industry in 1912 it was the headquarters for all visiting buyers many of whom travelled from as far abroad as Germany.
Famous Mines include: Alladin, Breakfast Creek, Cunnavalla, Exhibition, Little Wonder, Friday Creek, Gem, Hammond's, Seven Wonders, Scotchman, Stoney Creek, Top of the World, Quartpot...
Yowah – Home of the Yowah Nut
Yowah township is situated 165 km West of Cunamulla and has a friendly population of around 100 people.
There is a fossicking area for visitors, caravan park, golf course and numerous retail outlets and Opal cutters willing to help educate newcomers!
The greater Yowah Area also known as Cunamulla Mining Field, encompassing Koroit Opal Field, produces a whole sub-species of Boulder Opal, known generically as Yowah Nuts. The best examples reveal highly-prized solid cores of gem crystal. These small ironstone boulders or 'nuts' are found thickly embedded in the pipeclay band which varies in thickness from 15 centimeters to 60 cms.
This marvellous form of Boulder Opal includes a number of different nodule shapes and sizes which contain kernels of concentrically patterned and Opalised matrix.
The first lease was registered at the Yowah in 1884. Mines include: The Great Extended, Southern Cross....
Black Gate followed with the discovery of Opal on Dynevor Downs in 1894. Nearby mines include Leopardwood.
 Gem Yowah Nut |
 Yowah Nut Conglomerate |
Koroit - Situated (80km NW of Cunamulla) 50 miles north-east of Yowah, as the crow flies! Opal was discovered here in 1897 by Lawrence Rostron, the manager of Tilboroo station, Eulo. The field encompass the Red Star, Fiery Comet, Boobara and Holloways mines and produces brilliant Nut Opal, incredibly beautiful Matrix picture stones and red jasper-like Boulder Band capable of revealing brilliant faces of colour from thin horizontal veins of Opal.
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Sources & Image Credits: BEAUTIFUL OPALS - AUSTRALIAS NATIONAL GEM - SPECIAL 2000 COMMEMORATIVE EDITION, Len Cram, 1999. Opaline, Collection (Red Boulder Splits, Yowah conglomerate) THE LAST VOYAGE TO INDIA & AUSTRALIA, in the 'Sunbeam' 1886 - 1887, Longmans Green & Co. London, Anna Brassey, 1st Ed. 1889. WINTON by Bruce Hutchinson - Photographer, 2006. Opal Cutter Winton - November 1901, Photo coutesy of: Queensland Department of Mines & Energy. |
Opal Mining
The Geology of Opal Country
All the original finds throughout Australia were ‘floaters’ – pieces of opal, which had been eroded out from the horizontal opal levels within the desert sandstones. Weathered out from the high grounds on to the slopes and flats by wind, rain and ground movements over eons of time.
Faults are essential to the process of opalisation as they provided channels for the transport of water as well as barriers against water loss after mineralisation commenced.
Opal can be mined from the surface down to a depth of up to thirty meters, depending upon the height of the surrounding undulating country and the deposit of numerous opal levels.
Getting stuck into it!
To this day the Opal mining industry consists of numerous small businesses, partnerships and private individuals, invariably large corporations have failed in their Opal ventures. The mineral rights in Australia belong to the Crown, in order to commence digging for Opal a mining claim or lease 50mx50m or larger is pegged and registered. These days, application fees, annual rent, pastoral compensation, native title compensation and environmental bonds may add up to considerably more than $2000. Not so long ago you could have a go at mining for $50, however that still gets you a prospecting right for fossicking only, no digging allowed, enough to infect you with the opal-bug.
Most Opal mines are initiated by sinking shafts; this once took several days by hand, but now takes only an hour or so using Auger drilling rigs.
Having ‘bottomed’ on a promising level, a drive should be made to connect with a second shaft. This creates airflow and ventilation to avoid the very real threat of carbon monoxide poisoning.
All the while the miner is interpreting changes in the ground; dipping levels or opal profiles which could contain roof or toe levels or both; trying to drive across faults and looking to find 'traces' of Opal preferably leading up to ‘pockets’(patches of opal less than 1m wide) or ‘runs’(tens of meters wide) of Opal.
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Windlass, Pick & Shovel |
Auger Drilling |
Underground miners now use rotary tunnelling machines, diggers, bobcats and to a lessening degree jackhammers to remove the prospective ‘mullock’ or opal dirt. Mechanical hoists and ‘blowers’ (large vacuum extractors) now haul the mullock to the surface, having replaced the tedious hand windlass.
Most Opal is found by hand, gouging and checking the level, except at Lightning Ridge where the majority is found after the opal-dirt has been washed by an ‘agitator’. One in a row of large concrete mixers which sluice the sticky clumps of opal dirt at numerous tailings dam sites around the ‘Ridge’.
Professional Opal miners in South Australia employ heavy machinery and ‘Noodling plants’ to process discarded opal dirt and their own mullock; sieving and collecting the fines by conveyer into a dark room for UV inspection – as White opal fluoresces under Ultraviolet light. At all of the fields there are ‘noodlers’, tourists and locals, who fossick discarded mullock dumps.
In Queensland open-cut mining is preferred, employing bulldozers and excavators to cut wide trenches in the ground. Miners known as ‘checkers’ are required to walk behind and inspect the wake of the bulldozer or the excavator bucketfuls as the opal levels begin to surface.
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| Checkers looking for the emerging levels |
Crackin' a Boulder |
Once Boulders appear they are checked to look for traces of opal and may be cracked open using a small pick or geo-hammer. Hundreds of Boulders come up empty in search of that elusive fully loaded screamer!!!!!
Despite modern mechanisation, conditions are harsh in the remote deserts of Queensland. Working under the scorching sun with temperatures soaring above 50 degrees Celsius puts stress on the machinery as well as the courageous individuals who toil there, often hundreds of kilometres away from other settlements. Not to mention the blinding, suffocating dust made from tilling the dry earth and the swarms of flies so fierce that they patina ones shirt and find their way into every orifice.
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Sources & Image Credits AUSTRALIAN PRECIOUS OPAL, Archie Kalokerinos, 1971. (Diagram: Levels ,Slides & opal Formation) A JOURNEY WITH COLOUR Vol I&II, Len Cram (Photos. 3,4: Oldtimers, Drilling Rig) (Photo 5) OPALINE Pty Ltd (Photos.1,2,7,8) (Photo.2; 'Open Cut' mining operation: Showing Boulder Opal Levels behind Fault' - compliments the Kalokerinos diagram) |
Opal Miners Hall of Fame
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1) Black Drago 2) Bob & Branko 3) 'Tesla' Cindric 4) Jarra RIP 5) Col Duff 6) Gidgee Bill RIP |
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OPALTON CREW 7) Jerry Doktor & Branko Priebevich 8) Elisabeth Delarue tunneling 9) Wally 'Wombat' Lineck RIP 10) 'Tarzan' Antic |
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11) Kerry Jackson 12) Joe Kanny 13) James Hinds 14) Lilo & Meryl 15) Peter Christianos |
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16) Steve Ballard at 'Lina Glen' Jundah 1991 17) Joe Taranto in Opal Creek SEND US YOUR PICTURES AND WE WILL GET THEM ONLINE!!!! |
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18) Robson Wong, Ray Moore, Jack Hinds & Eric Lenton @ Hopal 19) 'Silky' or 'Jundah' Joe RIP |
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20) 'Fearless' Frank Tyne playing in PJ's @ Lina Glen 1993. 21)Yale Mercer & Nikita Apostoloudas @ Coathworth Mine operated by Opaline 2003 22) Bruce & Steve Ballard @ Scattery Creek 1988. 23) 'The Balkans Club' Milenko Kaljevic, Monty Negovanovic & Big Marko Uzelac, at the Tatts Hotel Winton April 2009. |
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1) Jim Megalos, Lenny Butts & Peter Christianos 1970 2) Bill Antoniades & Elias Christianos watching a Kokatha tribesman charring a Roo tail. 3) George & Zoe Christianos c.1958 4) Emannuel, Peter Christianos & Crew 5) Ross Christianos, Bill Antoniades & author P.Vin Wake 6) Andamooka - the bare essentials! 7) Greg Sherman and American David Caplan inspecting thousands of ounces of Spencer Dunstan's Opal in 1962. |
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8) Oldtimers Hut Andamooka 9) Crocodile Harry spent 13 years hunting crocs before trying his luck in Coober Pedy where he resides in his famous cave. The real deal Opal Dundee! 10) Jago Jozic preparing gelignite sticks 11) Ray Rhiney pegging on old Mintabie airstrip - Claim No.51. The last release of the airstrip & no opal there *#@^!!! 12) Farid Khan(right) & Abdullah Chan, Opal Hotel Coober Pedy ca.1972, photograph by Bruce Howard
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13) Margret Mackay editor of 'Coober Pedy Regional Times' tumbling 14 mile find with partners Steve & Jimmy Efstradiou 14) John & George Doumtzis 15) Ken Male of Coober Pedy with BT a Mintabie girl & tour guide & Trevor Richter Miner from Mintabie
16) Chuck another snag on the barby!
17) Zoe's yard
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| 18) 'Carpooling' to the Opalfields in the late fifties | |
Opal mining has long attracted eccentric individuals. The baffling nature of Opal occurence captivates their creative genius and the harsh beauty of the Australian outback sustains them in their quest!!!
LIGHTNING RIDGE Miners (1900's On)
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1) Opal Miner at his campsite, Lightning Ridge NSW, 1911.
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 2) Digger's Rest Hotel, ca.1972, photograph by Bruce Howard
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3) Stephen & Mary Aracic, 2009. Author of 'Determined' first mined at Lightning Ridge in 1965 and still mines today!
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Sources and Image Credits: B.5) OPAL MEN, P. Vin Wake, 1969. B.18) 'Carpooling' to Coober Pedy in the fifties. Photo courtesy of Stella Samaras B.17) Zoe's yard. Photo courtesy of Stella Samaras B.12) Farid Khan(right) & Abdullah Chan, Opal Hotel Coober Pedy ca.1972, photograph by Bruce Howard used with permission by the artist, taken form Australian Pubs Collection, nla.pic-vn4361734 the National Library of Australia C.1) Opal Miner at his campsite, Lightning Ridge, 1911. B & W Photograph by E.C.Kempe. nla.pic-vn3801038 used with permission from the National Library of Australia C.2) Digger's Rest Hotel, ca.1972, photograph by Bruce Howard, taken form Australian Pubs Collection, nla.pic-vn4361361 used with permission from the artist. |
Opal Miner's Glossary
| Alluvial | Opal found at or near the surface of the ground in the build up of sediments (alluvium) which have eroded out of the sandstone mesas and deposited in the flats below. Considered by many miners to be the hardest and most stable Opal. |
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Amber |
An Opal type with moderate to strong amber colour potch. Also referred to as ‘beer-bottle’. |
| Andamooka Matrix |
Pale matrix which can sometimes be treated to appear like Black Opal. |
| Angelstone | A hard highly silicified sandstone lump or nodule, it is usually associated with pockets of nobbies in Lightning Ridge and pockets of shells may occur under them in Coober Pedy. Hard semi-spherical or lenticular pieces of (diatomaceous) porcellanite also called walnut stones or by a term first used at White Cliffs - "guardian angel stone". |
| Ballroom | A large underground chamber or open area of worked ground. |
| Band | A hard siliceous band of sandstone either at the base of a sandstone stratum, or floating within a clay level. It is usually bleached or stained brown and often carries opal beneath it. |
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Bar |
A solid piece of Opal colour running through potch, a very good specimen being a centimeter or so thick. Also refers to an establishment where the Opal miner can usually be found when not mining. |
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Barry |
Bars of potch found alternating with bars of precious Opal in the seam or nobby. |
| Belemnite |  An extinct member of the mollusk family known as cephalopodae, whose living relatives include squid and cuttlefish. Rare fossils of these cretaceous sea creatures have been replaced with gem Opal. Fossil belemnites are the internal shells of the marine invertebrates, they are tapered, cylindrical tubes and mostly hollow at one end. |
| Biscuit Band |
A flakey, crumbly sandstone, either found cropping out on the surface or quite shallow. Essentially these are alluvial deposits of silt and stone washed out from nearby hills. Most miners consider that they consist of slides of Opal dirt. They may be 10-15cm or more in thickness and appear to go down into levels of opal dirt. They may contain good Opal. In some places they are even found penetrating into black soil. |
| Black-Crystal | Opal type which is partly transparent from some angles of view. From other angles a rich royal blue flash appears making the Opal opaque and appearing like Black Opal from those angles. |
| Black Opal |
Opal type pertaining to Opal that is dark in colour. Some are black in their own right, others with transparent faces have a black back. The natural black potch backing is the main criterion for the term Black Opal. |
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Block out |
To section an Opal in the lapidary process by sawing mostly. Particularly a |
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Blocky |
Ground which is dark-coloured (reddish), crumbly, iron-stained type of opal dirt which comes away in large blocks. |
| Blow | Some miners use the term to refer to well weathered sandstone or mudstone appearing on the surface. Others restrict it to where it appears that chunks of sandstone were 'blown' to the surface through the deeper layers. Below ground evidence in support of this can be seen in the nature of sandstone chunks mixed with Opal dirt and other rocks and penetrating all layers. Opal often forms in the vicinity of blows. |
| Blower |  A machine developed at Coober Pedy to extract mullock from underground. Resembling a huge vacuum cleaner in operation. It sucks out the dirt from the underground mine before blowing it out the back end into a hopper which then dumps the dirt on the surface. |
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Blue Opal |
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Bluebottle |
Transparent blue potch found mainly in association with |
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Bodgie |
The name given to the level closest to the surface. Under this is the squibby, then the main, then the bottom level. Mainly a South Australian term, it is also known as ‘top’ level at Lightning Ridge, followed by ‘second’ until bottom is reached. |
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Bony Potch |
Mainly a South Australian term pertaining to white powdery potch so named because it is said to represent the bony remains of marine creatures. Like thin Opal and potch generally it is only referred to as a trace. |
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Bottom On |
To dig a hole either by hand or machine and hit Opal at the bottom. |
| Bottomed | Having reached the first level (or bottom level) of Opal dirt after sinking a shaft which has usually passed through layers of sandstone and hard band. Bottom is also used to describe the lowest of several levels (known as bodgie, bottom & main in that order). |
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Boulder |
Mainly pertaining to Queensland Opal occurring in thin veins through, or facing on, hard grey or brown ironstone boulders, which may be very small like an almond or up to 10 meters long and nearly half a metre thick. The Opal can occur between the layers of rocky material which is built up something like an onion, or in pipes, nuts, or kernels, depending largely on the type of boulder structure in the area. |
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Brick-pipe |
Cylindrically shaped section up to about 2 meters in length, filled with siliceous clayey material in which common Opal is found ramified in all directions. |
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Brilliance
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A general feature of gems, determined in Opal by the intensity of light emerging, the presence of potch, colour and its type and proportion, and the amount of ‘milkiness’ in the Opal. |
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Broken Level |
Where there is no definite roof. The Opal dirt is jumbled up with sandstone. |
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Bug-hole |
Holes usually caused by air, but also used loosely to refer to sand-holes, which interfere with the complete formation of Opal. |
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Burnt |
Usually in the expression ‘burnt rock’, when the material is showing only minute Opal traces and has been ‘beaten’ by matrix in the case of seam and nobbies or dry empty voids in Queensland boulders. |
| Cabochon | The most common form of gem cutting, in which the stone is cut with a flat bottom and a rounded top or 'high domed' face in cut Opal. |
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Candle-box |
Poor Opal not really good enough for sale as quality gems. It was stored in candle-boxes at White Cliffs which produced prolific amounts of the stuff. It was sold for as little as £1 per box, Opal Miner, |
| Carat | A troy Metric measurement for weighing gemstones. One carat equals 0.2 grams (5carats=1gram). |
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Cat’s-eye Opal |
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Chaff |
Pattern type with the appearance of straw sprinkled on the Opal surface, each grain of straw with lineal striations. |
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Chinese-writing |
Pattern type showing one or more shapes which look like Chinese symbols. |
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Chisel-pick |
A small specially made Opal miner’s pick with chisel points at both ends of the head. See Gouging-pick. |
| Chips | Small segments of Opal. |
| Chipping Opal | Snipping the edge of rough to display colour and clarity. |
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Chrysoprase |
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| Claim Jumping | Applying to the Mines Warden to obtain another miner's claim, usually for not renewing it or fulfilling the conditions of the lease, which may include working it. |
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Class |
To grade the Opal into firsts, seconds and thirds according to quality. A term from |
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Cloud |
A film sometimes found affecting the brilliance of an Opal. Usually matrix or ‘scum’ this will usually grind away during the lapidary process, however if the cloud goes right through the colour it may be potch and cannot be removed. |
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Clover-leaf |
Type of pattern usually in a small stone, in which a central grain/unit/particle is surrounded by rings of outer units. |
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Collar |
That part of the band or hard sandstone roof through which the shaft breaks into the Opal dirt. It varies] from 1 centimetre to half a meter, averaging about 10 cm. Also pertains to the timber framework placed around the top of the shaft. Sometimes there is an outer and inner collar separated by dirt for extra strength. |
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Colour |
The spectral colours which play in precious Opal or the several potch colours. The difference being that potch is flat like paint, and does not radiate light as does the colour in precious opal. |
| Colour Bar |  A layer of precious Opal sandwiched between potch or on top of potch. Also applies to a vein of precious opal in boulder or nut type Opal. Two or more horizontal parallel bars of colour may be running through a piece of Opal. |
| Common Opal | Generally called potch, does not display the phenomenon known as play of colour. May be found in various body tones from black to white and lemon yellow, orange, red green or sky blue. Not precious, as it is not very translucent and has no play of colour. However some are not common at all and are increasingly being used for ornamental purposes. |
| Concrete |
In Andamooka this refers to the conglomerate band at the kopi-mud interface, which is the main host rock for opal. In Queensland this may refer to 'Fairystone' aka Colour-Concrete which is opalised sandstone(Quartzite) akin to Andamooka Matrix but generally more porous. |
| Conglomerate |
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| Craze | Opal with a high water content and considerable impurities may have a tendency to crack profusely in a web-like pattern usually not long after it is cut and polished. |
| Crockery Caps | Found on some nobbies, they consist of white potch Chinese hats on top of the nobby. They are a sign of good Opal if the bottom of the nobby consists of black or opaque blue potch. |
| Crystal Opal |
Opal type, semi-transparent and semi-translucent without milkiness and exhibiting a moderate to rich play of colour. It is superior to jelly,but inferior to semi-black and black-crystal that contain richer colour play. |
| Datum Post | The nearest reference point fixed by the Mines Department from which a claim's boundary are measured. The advent of handheld GPS has lessened their importance. |
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Deep-country |
In contrast to shallow country, an area in which there might be a half a meter of soil and gravel, then up to 5m of hardened claystone and shincracker, up to 23m of sandstone, then band up to 25cm. Below this is the first level of 1m or so of clay and Opal dirt. Below this there might be successive layers of 1m or so of sandstone and thicker levels of Opal dirt. |
| Digger |
Also a New Zealand and Australian slang term for soldiers. Derived in WWI as ANZAC troops were especially good at digging tunnels between their own trenches and the enemy's. It is a compliment to be referred to as 'digger', because it indicates you are good at a very difficult job, whether you're a miner or a battler 'dig'! |
| Dobbing Stick | Opals and gemstones are stuck on to such sticks for cutting. The stone is either glued on or lapidary wax is used, once dopped the stone can be more easily manoeuvred. |
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Dog stones |
Lumps of sandstone hanging down just below the roof (~10cm) and regarded as a good sign. |
| Dome | The sandstone roof of an underground mine may be shaped like the inside of a dome. Opal tends to occur in the levels beneath this. |
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Doublet |
Manufactured stone with a single slice of translucent Opal adhered to an artificial back of either ironstone (referred to as |
| Drive |  An underground tunnel, leading from a shaft or ballroom. |
| Dry Level | Also known as false level, usually the first level from the surface, dry in appearance and non-productive. |
| Duffer | A shaft sunk on mixed level or a mine which produces no opal. |
| Dugout | A Miner's residence dug into the side of a hill. Provides excellent insulation from the extremes of the desert climate. |
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Dump |
The mullock and dirt heaped up near a shaft, or around and at the end of an open cut. These are often screened or prospected for odd pieces of Opal which have been missed. |
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Exploding Flash |
Rare mobile pattern which appears to explode in all directions as the stone is moved. |
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Occurs when opal in fills a cavity or bug-hole which has the effect of looking like an eye because of circles of colour around it. 'The Flame Queen' found in Lightning Ridge displayed this most unusual colour pattern; it can be described as having the appearance of a fried egg. |
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| Face | The wall of a mine in the direction where the miner is headed in expectation of finding opal. |
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Facing |
Or to ‘face up’ as applied to stones, to clean up, grind away any dirt etc. from the stone so as to reveal the appearance of the colour and pattern for sale. Not all stones ‘face’ or show colour when looked at from any angle, some stones only show full colour from one, sometimes, oblique angle. |
| False Level | A clay level just above the main level where it is not expected to be. |
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Fault |
Fracture resulting from earth movement. Gems may form in the material of a fault or slide (Lightning Ridge) or opaliferous material may fill a slide ( |
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Fern |
Pattern type also called ‘tree pinfire’. |
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Fire |
Sometimes called live opal, a name used to describe an Opal with good play of colours, usually with vivid red predominant. |
| Fire Opal | Correctly applied to Mexican Opal of volcanic origin with a red-orange body tone. Some times used to describe red play of colour. 'Fire' is sometimes (erroneously) used as a synonym for precious or the 'play of colour' phenomenon. |
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Firsts |
A South Australian word for opal of top quality also referred to as the ‘tops’. In Lightning Ridge better known as gems. |
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Flagstone |
Opal pattern with numerous irregular colours resembling flagstones in their arrangement. |
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Flash |
Aka. Flash-fire pertaining to Opals whose light shows a single flash in a large patch of colour. It may move in one or several directions. See rolling-flash. |
| Floater | When common or precious opal pieces, nobbies, seams, pipes, nuts, matrix or fragments of boulder opal are eroded out of their original host rock and found in creeks and as lag material in gullies or on scree slopes close to mesas or escarpments. Also called 'Top Show'. |
| Floor | The bottom of a drive or tunnel. |
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Floral |
Opal pattern type with rounded irregular grains of colour, larger than pinfire and having the appearance of a floral design. |
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Fossicker |
One who digs unsystematically or only in a small way, usually covering ground worked by others. |
| Foul Air | Stale air in which, due to a lack of ventilation in the mine, poisonous gases can build up. |
| Free Form | A piece of Opal where the natural shape of the stone has been retained when cutting, often to avoid wasting weight for the sake of a popular shape. |
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Full-colour |
Colours clear to see and obviously good, especially when evident without viewing from special angles. |
| Fun Stone |  Low to medium grade, Boulder Opal in particular, where potch, ironstone and scene-like inclusions are retained in the cut and polished piece. Similar to 'F#%@ Stones' given away by eager miners to attractive lady visitors. |
| Gad | A long hand-held steel chisel for drilling holes in hard ground for explosives, by tapping with a hammer. Used extensively by the 'Old timers'. |
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Gemmy |
Aka. Gem, Opal of top quality for use in distinctive jewellery. |
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Geo-hammer |
Or Geologists pick, different from that required for Opal gouging, but reasonable good for splitting smaller boulders. |
| Gibber | Rounded wind polished pebbles or cobbles of silcrete, quartzite and ironstone, forming a surface layer or pavement. Characteristically reddish-brown owing to a concentration of iron oxides on the surface. |
| Gidgea |  A tough outback species of native tree, Acacia cambagei, also known as 'stinking wattle' as it emits a pungent scent particularly when rain is imminent. Gidgea trees generally line watercourses on stony gibber plains. |
| Ginger Whisker | An inclusion in white Opal rough from Coober Pedy. A form of cracking which results in right angular cubes breaking away from the stone when it is cut. |
| Gouge | When the miner is digging out opal, prying it loose from the Opal dirt, or digging with a pick in anticipation of striking it. |
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Grain |
This may refer to pattern as seen on the face of an opal or the particles, units or patches of colour which make up the stones overall pattern. |
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Grass |
Pattern type similar to straw pattern but with thinner units and lineal striations. |
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Gray |
White or grayish Opal often found in match box sized pieces in Coober Pedy. Usually quite opaque until it is sliced very thinly to produce triplets and mosaics. |
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Greasy-back |
A section in and above the Opal dirt which may fall in. It is usually caused by penetrating water making the sandstone greasy and likely to slip away. Also a term referring to oldtimers. |
| Greybilly | A dense, massive silcrete generally grey to greenish grey or creamy coloured. Also referred to as Shincracker this highly silicified rock is found towards the surface at certain fields particularly in Coober Pedy and Lightning Ridge. |
| Gun Claim | A term used to describe a rich claim or the top claim in a field. |
| Gypsum | Commonly found in association with Opal on all the fields. Either as sheets or small to large clusters. Also an inclusion in Opals of all types. |
| Harlequin |  The most desirable pattern in Opal, similar to a checkerboard mosaic. The grains of this pattern are squares of different colours which change as the stone is moved. |
| Hyalite | A glassy, transparent form of common Opal. |
| Ironstone Band | Is found in some areas adherent to the bottom of the sandstone in sheet form. This hardened layer can be a significant continous level, producing matrix and some exceptional stones can be cut from fine veins of colour |
| Jasper | Hard tough, silicified grey shiny rock boulders or layers. |
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Jelly |
A type of Opal with almost transparent potch colour, perhaps slight blue or green, and a weak play of colour if any. |
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Jeweller’s shop |
The name given to a rich find. |
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Kernel |
Opal inside a kernel boulder. |
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King-stone |
Also a Queen stone, a superior stone which stands out in a patch or pocket. |
| Kopi | Grey, silty, clay-like sandstone or fine-grained gypsum. |
| Lapidary | A cutter, polisher, carver or engraver of precious stones. |
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Lead |
Opal with good colours but having a dull leaden finish. Opal with a slightly translucent grey back and may be suspect as far a stability, cracking etc. are concerned. |
| Level |
Within the Opal profile, generally no deeper than 30 meters, numerous levels occur. One or two are usually productive levels, however some rare systems may show up to 10 levels with 5 or 6 of them producing some colour. |
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Londoner |
A shaft which breaks through into a drive of someone else’s claim workings. |
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Looks at you |
Said of a good stone when good colour is seen from any angle. |
| Main Level | This term is usually restricted to the level that happens to carry the most Opal. |
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Make |
To form, develop into, be present. Thus some potch ‘makes’ into gem Opal. When the level makes Opal, the miner has struck a deposit of Opal. |
| Matrix |  Where there are only small flecks and veinlets of precious Opal in opaque matrix. Used to describe flecks or veins of colour in quartzite (Andamooka matrix/Fairystone) or ironstone (Boulder matrix). |
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Matrix-lines |
Lines of matrix material which appear between grains of colour in the face of an Opal, and are the cause of cracking. Sometimes confused with potch-lines which do not cause surface cracks. |
| Mesa |  Flat top ranges or hills. |
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Milky |
Or milk Opal is the white variety which displays subdued pinfire effects and patchy colour. Milkiness is an Opal quality which detracts from brilliance and sharpness in the play of colour. |
| Monkey | Refers to a shaft which is sunk underground in a drive to gain entry to a lower level. It does not go directly up to the surface. |
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Mother-o’-Opal |
Another name for matrix, especially a kind of Opalised sandstone material found in |
| Mud Boulder | Fine grained ironstone boulders containing thin cracks which may carry good quality dark Opal. |
| Mud Level | Non productive clay level. The last clay level, the miner does not expect Opal to occur beyond this depth. |
| Mugstone | Or 'muggy' is a Lightning Ridge term for low grade Opal. Generally refers to stones below commercial grade. |
| Mulga |  A native wattle tree, Acacia aneura, which covers a large proportion of the Australian semi-arid savanna or shrubland. The species has a long life and extremely hard wood. |
| Mullock | Opal dirt that has been dug up and removed, then dumped around the shafts or pushed out of open-cuts. |
| Natural Joint | In seams or fossils when 2 or more pieces, from a pocket, fit neatly together (like a jigsaw puzzle) in the ground. |
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Nest |
A collection of |
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Nigger head |
Hard spherical masses of fine-grained silica ranging up to fifty or more kilos in weight. |
| Nobby |  A rounded opal concretion found in clay, particularly at Lightning Ridge. |
| Noble Opal | An old term for precious Opal. Noble is a qualifyng term used generally in mineralogy to express fineness and superiority. |
| Nodule | Rounded or ovaloid concretions generally harder than their host rocks. Nobbies and Yowah nuts are nodules. |
| Noodling | Looking for Opal in mullock heaps and open cuts. |
| Opal Dirt | A common name to describe sandstone, shale and clay levels which carry Opal. |
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Opalite |
Used to refer to a plastic opal simulant. Also used as another name for Volcanic Opal aka. Mountain Opal, as distinct from sedimentary Opal found in sandstone. |
| Opal Fever | An addiction, once found Opal enters the blood stream, a good miner never gives up! |
| Opal Field | A mining area that has several working and/or historic mines and has been named and recorded by the mines department as a field. Opal fields are divided into large districts such as Coober Pedy, Winton, Lightning Ridge. then they are subdivided into smaller areas such as 8mile, Opalton, Coocran. Generally these sub-fields are less than 10 square kilometers and no less than 1km square. |
| Opalessence | Properly used this denotes a pearly shimmer often shown by common Opal. It is caused by the scattering of light. It can also be observed in moonstone, chrysoberyl and opal glass. |
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Open |
To cut open a piece rough opal or split a boulder. To determine where the best colour lies so that the most attractive jewel can be made. |
| Painted Lady | A boulder, generally of quartzite (concrete), which splits along a fracture to reveal a thin coating of Opal, these are found at Andamooka. In Queensland ironstone boulders of this ilk are termed splits or specimens. |
| Pancake |
This type of ironstone concretion is highly prized by miners in Queensland. Generally shaped like a discus, they are dense and fine-grained rocks, of a chocolate brown colour. |
| Parcel | Numerous pieces of Opal offered for sale as one lot. This may be rough or cut and usually constitutes one type of Opal from a pocket or patch; or a period of the miner's production. |
| Patch | An Opal occurence consisting of a series of rich pockets forming one after another, generally coming from one lead. |
| Pattern | The arrangement of grains of colour as they appear in a stone. Patterns which display larger grains are rarer and more valuable than smaller patterns. |
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Pea Opal |
A small stone about the size and shape of a dried pea. Rough pea nobbies are found at lightning Ridge and levels of very similar shaped stones have been recorded in Coober Pedy. |
| Pegs | Used in 'pegging' a claim, this can be done with 1 or more wooden or metal stakes, usually four are used. The laws in each state govern the exact regulations and claim dimensions allowed. |
| Pennyweight | Used to measure the weight of rough Opal. Equal to 1/20 of a Troy ounce and approximately 1.555 grams. |
| Picture Stone |
Opals which display a picture with their pattern, sometimes in conjunction with inclusions or structure lines, that reminds us of a specific object. Whereas most patterns are often repeated, picture stones are rare and more unique. Picture stones are given names which reflect the specific images they portray. |
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Pigeon’s blood |
The name for the deepest coloured red Opals. The miners describe red colour as ‘ox blood’, ‘pigeon blood’, ‘port wine’ red and so on down to ‘rose pink’. |
| Pillars | When underground mining if wide drives are made pillars of untouched dirt must be left as roof props to ensure safety from a potential collapse. |
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Pincers |
Used to clip off the edge of a rough seam or nobby to see if good Opal is underneath. Usually called Snips and also referred to as nippers. |
| Pineapples |  These pseudomorphs are Opal replacements of glauberite or ikaite crystals. They resemble miniature pineapples and are found exclusively at White Cliffs NSW. |
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Pinecones |
Opalised cones, stem and root fragments of primitive pine and cycad-like plants are common in Lightning Ridge. Mostly small varieties ranging from 10-30mm, there are various species. Usually compressed and slightly flattened, their scales are a diamond or half-moon shape. |
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Pink Opal |
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| Pipe Opal |
Queensland's Opal fields produce both Pipe Boulder Opal and free Pipe Opal in sandstone.
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A small concentrated area of Opal. Not more than 2 or 3 meters square. Also referred to as a 'nest'. A patch is a larger occurence consisting of a series of rich pockets forming one after another, generally coming from one lead. |
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| Potch | Common Opal, does not display the phenomenon known as play of colour. May be various body tones. |
| Potch & Colour | Potch in which patches of precious Opal occur, generally refers to low grade rough suitable for ornaments. |
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Potch-box trade |
The buying up of tones of mainly low grade Opal, for sale overseas. See also Candle-box Opal. |
| Puddling |  To process Opal dirt for recovery of Opal. In Lightning Ridge today this is most commonly done with the aid of water in an agitator (similar to a concrete mixer)which produces a slurry. The older dry method uses mechanical sieves or rumblers. In South Australia small rumblers are used with water and 'noodling machines' are a popular dry processing plant. |
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Puddling tank |
A large dam at which wet puddling takes place. Miners rent sites where they operate power-driven wet puddlers capable of handling several tones of dirt in one operation. |
| Precious Opal | Opal that has the prismatic play of colour for which the gem is noted. Without changing colours, it is not precious. Precious Opal is not the same as Fire Opal. |
| Pseudomorph | A mineral which takes the form or shape of another mineral which it has replaced by substitution or by chemical alteration. |
| Ratter | A thief who works another miner's claim after hours. |
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Red coming out of blue |
An appearance of this happening with these two spectrum colours as the Opal is moved. |
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Red on Black |
An aspect of the foreground and background colour in which spectrum red colour pattern overlays a backing that is black potch. |
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Reptile Skin |
Opalised reptile skin are rare fossil remains. These display overlapping scales of irregular size and delicate wrinkles. |
| Rickshaw | A two-wheeled trolley underground miners use instead of a wheelbarrow to convey dirt to the bucket at the shaft. |
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Rolling-flash |
A mobile pattern in which a flash of colour rolls across the stone as it is moved. There may be more than one apparent. Although usually arranged in parallelograms the direction of movement can vary. |
| Roof | The top of a drive, usually the base of the sandstone where it overlies the Opal level. |
| Rough | Raw Opal which has been freed of dirt but has not been cut. |
| Rubs | Opal Rough which has been ground or 'rubbed' down to the colour bar. Either done quickly to obtain an idea of the likely quality of the gem or in careful preparation to cut and polish the stone. |
| Rumbler | A meshed cylindrical drum, of various proportions, mechanised or manually operated, to sift Opal dirt. |
| Run | Opal formation tends to 'run' in front of a slide for the length of the slide. Opal may occur in all or only one level, a run is most likely to occur on the main level. However most of the Opal formed is usually potch and only a little is precious. |
| Runner | A commission agent employed by the miner or merchant to sell Opal on their behalf, where the source remains anonymous. This term is most commonly applied when the dealings are done at the Opal fields. |
| Rush | Newly discovered Opal prospect where miners hurry to peg claims. |
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Sand-pit |
A lump of sand in an Opal stone which leaves a sand-hole when removed. These are often minute and need to be treated gently by the lapidary, so they do not become enlarged or the stone ground to oblivion. |
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Sand-shot |
A fault occurring when a stone is marred by sand inclusions, these damage the appearance and value particularly if seen from the face of a gem. Often these appear only upon cutting. They present a challenge to the lapidary and may cause pitting in the surface of the stone. |
| Sandstone | Opal bearing rocks vary in nature from field to field but are usually a form of desert sandstone. |
| Sandy Boulder |
These boulders are coarser grained and lighter than the denser fine-grained ironstone boulders. Sometimes they are referred to as 'salt & pepper' boulders. Usually they are associated with the Quilpie mining district, these boulders occur on different levels across the Queensland Opal fields. They occur in the largest sizes of all boulders, sometimes several meters across. |
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Screening |
A method of noodling in which a wire screen, bed frame, perforated drum or anything providing a mesh is used to shake out dirt and leave concentrates to be checked for Opal. |
| Scum | A rare fault which is not apparent in freshly cut stones. With age a film ('scum') appears over the surface, resulting in a loss of brilliance. This may be removed by repolishing. |
| Seam Opal |
Narrow seams of precious Opal that has formed in fissures and cracks in the host rock. Formed in more or less horizontal (or vertical) seams varying from paper thin traces to slabs more than 10cm thick. Jelly, milky opal, white opal, grey opal, crystal opal and semi-black opal occur as seams, generally of irregular shape.
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| Sedimentary Opal | In Australia all of the commercially produced Opal is formed in the vast desert sandstones which have undergone extensive weathering. |
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Semi-Black |
An Opal type with stronger concentration of potch colour than crystal and in which the Opal is only just transparent. The Lightning Ridge semi-black is any variation between light and black Opal, it is nearly always very bright, and can be very valuable. |
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Shallow country |
In contrast to deep country, a landform with a meter of soil and gravel to the biscuit band up to 3m thick, followed by possible sandstone up to 1m or more thick over the first dry level of Opal dirt. |
| Shell |
Opalised marine fossils occur as full or partly replaced shells with sandstone cores, varieties include; bi-valves or clams, snail, turritella or whelks and cockles or mussels. |
| Shincracker | Also known as silcrete or greybilly this term was applied by hand miners. When they struck the rock with their picks it would shatter and splinters would strike them in the shins. |
| Show | Or 'Opal Show' is a term used by miners to describe an Opal prospect. |
| Silcrete | Any rock cemented (silicified) or replaced by secondary silica. |
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Sinking pick |
A heavy pick used o break up hard top-rock while sinking a shaft by hand. The sinking pick blunts considerably faster than the driving pick. |
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Skin shell |
When entire these look like a solid Opal but only has a thin skin of Opal (probably where the original shell was), and an inside composed of sand. |
| Slide | Slippery or Slippery back, any slide on an angle that seperates one level from another. Some call it a slip or a fault. |
| Slip | A small secondary slide which runs more or less parallel to a major slide and cracks the ground sufficiently to permit the deposition of good Opal. Sometimes called a 'sleeper'. |
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Smoky |
A translucent type of potch, blackish, sooty in nature, and providing the semi-dark background for the star-flash pattern in precious Opal. May also be used to describe a hazy appearance without clear-cut colours which can lower the value. |
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Snips |
Used to trim of the edges of rough to ascertain quality. An essential tool for the Opal digger, something like a pair of pincers with sharp jaws, used to remove a small section from the edge of a rough seam or nobby. |
| Solid | Natural formed precious Opal of one piece. |
| Specking | Searching for Opal missed by the miner on old mullock heaps. |
| Spotter | A person who walks behind a Bulldozer looking for signs of Opal during excavation. Also referred to as a 'Checker', in Queensland they hit the boulders as they come up in the level, to find traces. |
| Squibby Level | And 'bodgie level' are early sub-levels that occur above the main level, they may make smaller pockets but are not as prominent, continuous or productive. Also may be referred to as 'false level'. |
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Star Flash |
Type of pattern with a play of colour on semi-translucent smoky potch which gives an effect like stars in a semi-dark sky. |
| Step | A fault in the level where the roof drops suddenly at a right angle for a meter or more, then continues horizontally. Also known as a 'wall', such a drop is regarded as a favourable indication. Opal may be found on its high or low side. Steps may be anything from a meter to 100 meters long. |
| Stow Dirt | Loose dirt which is removed from the face but left underground. Usually stowed in disused drives. |
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Straw |
Type of pattern with the appearance of flat pieces of straw overlapping irregularly. |
| Structure lines |  Lines in an Opal where the internal structure of the Opal, the size and/or alignment of the silica spheres, has changed. Not cracks. These often provide the basis for unique designs or patterns as seen in picture stones. |
| Sun-flash | Colours in Opal that can only be seen in sunlight. Such Opal does not have colour bars but resembles jelly or amber potch, it may also be black based. |
| Tailings | The material which is left over after the miner has sorted through it, by processing a load of Opal dirt in a wet or dry puddler or in a noodling machine. |
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Teeth |
Encompassing toothplates and jawbone fragments from lungfish, teeth from sharks, crocodiles and dinosaurs have been found Opalised at numerous fields around Lightning Ridge and to a lesser extent in |
| Toe Dirt | As miners gouge the Opal dirt falls at their feet, it is called toe dirt in contrast to the Opal bearing level known as 'pay' dirt. |
| Top Show | Surface trace and/or floaters indicating an area prospective for Opal. |
| Trace | Thin or small pieces of potch or Opal which pinch in and out and may lead to a pocket. Hopefully! |
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Treated |
Usually in the expression treated Andamooka Matrix, which is a pale porous matrix with little dispersed Opal, but able to be converted to an appearance of solid black Opal by a process of dehydration and treatment with sugar and acid which deposits carbon in the pores. Queensland Boulder or Band Matrix is not the same, it polishes beautifully without treatment. |
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Tribute |
One’s share when working on a partnership basis, that is as a tributer. The owner of the mine is usually a silent partner who does not work at the mine but is paid a percentage of the Opal, the tribute. |
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Triplet |
A manufactured stone made of Opal as a part of three layers. A thin slice of Opal is sandwiched between a black potch or plastic backing and a domed quartz or plastic capping is adhered to the face to act as protection and a magnifier. |
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Troy Ounce |
(Ozt) is a unit of imperial measure. It is still most commonly used to gauge the weight of precious gems and metals. There are 20 penny weights to a troy ounce or 155 carats. 1 troy ounce = 31.1034768 grams |
| Tucker Money |
A parcel of Opal which puts food (known as 'tucker' to the bushman) on the table and if you're lucky some fuel in the tank! To get 'beer money' the miner needs a good find or the Publican’s still buying!! |
| Tumbling | The simplest form of gem cutting, in which the rough mineral is put into a revolving barrel with progressively finer abrasives, until a polish is obtained. This process closely resembles what happens to rocks in a stream, except that it results in a higher level of polish. |
| Tunneling Machine |  A machine which coupled to a blower can carve out drives and ballrooms including underground dwellings, particularly well suited to working the hard and stable sandstones of Coober Pedy. |
| Turkey’s nest |
A mess at the bottom of a shaft as a result of collapsing dirt, timber etc. |
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Twinkle |
Pattern of small separated star-like colours, rather like a scattered pinfire. |
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Vertebra |
Fossilised bones are not uncommon on the Opal fields the largest and most recognizable of which are vertebrae replaced by Opal. Opalised dinosaur bones have been found at white Cliffs and |
| Vertical Opal | A seam of Opal which is found in situ laying at a vertical angle as opposed to the more common horizontal formation. Vertical Opal will only face on its thinnest sides as the lamellar patterns run across the stone instead of along it. |
| Verticals |
A vertical structure of clay several centimeters wide, usually in sandstone or Opal dirt. Verticals provide a conduit for water entering from above to form Opal below. Also known as 'feeders'. Vertical seams represent cracks or faults in the sandstone which may also be refered to by miners as 'blows'. |
| Volcanic Opal | Opal which has deposited in former volcanic areas and in association with volcanic rock. Believed to contain a high percentage of moisture. |
| Wood Opal |  Wood that has been replaced by Opal. Also referred to as 'wood replacement'. |
| Webbing | A fault which can grow somewhat like a spider web. It tends to follow pattern lines. In some cases this may be removed by repolishing, however it will invariably reoccur with the overall effect being loss of brilliance. |
| White Opal |
Opal type also known as Light Opal, has a body tone ranging from milky white to translucent. The most common variety found at most fields and mainly at Coober Pedy in South Australia. White Opal, with its lighter to whitish body colour, gives the full colour array in an opaque background. |
| Windlass | A hand winch for hauling up dirt out of the mine shaft. |
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Yabby buttons |
Opalised crayfish gastroliths. Known as ‘fish-eyes’ to the miners at Lightning Ridge where they are common throughout the fields. They range from a few millimeters up to 20mm in diameter, indicating yabbies up to 300mm in length. |
| Yapunyah | Ghost Gum tree native to semi-arid Queensland found atop rocky mesas growing on faults and fractures from whence they get moisture and nutrients. |
| Yowah Nut |
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Volcanic Opal Miner's Vocabulary |
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| Cachalong | Porous and opaque Opal that will absorb water quickly. |
| Cherry Opal | Cherry red ground colour. Occasionally has play of colour. |
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Contra Luz |
Opal, usually from Mexico, which shows its best colours against the light. |
| Fire Opal | Translucent Mexican Opal with red or orange overall colour. Not synonymous with precious opal. If the red Opal has play of colour, it is precious fire Opal. |
| Girasol | Water clear Opal with broad floating colours. |
| Hyalite | Pure, transparent colourless Opal that has formed as crusts. |
| Honey Opal | Pale Amber-coloured Opal, usually with play of colour. |
| Hydrophane | Opal that appears opaque and lifeless until it is immersed in water and slowly becomes more translucent until, in some cases, it becomes totally transparent and shows play of colour. Most commonly volcanic in origin, from Indonesia or Mexico. |
| Jelly Opal | Translucent colourless Opal with play of colour, a variety of precious Opal. |
| Milk Opal | Lechosos or Milky Opal. with play of colour against a pure white ground colour. |
Peruvian blue Opal is an opaque, pastel blue gemstone. This monochrome Opaline material does not exhibit the play-of-colour which characterises precious opals.
A variety of chatoyant yellow Opaline material, without play of colour, is found in 
This apple-green to emerald-green Opaline material is found as large seams and nodules mostly in 
Also referred to by miners as 'Puddingstone', is a rock made up of pebbles and other rocks such as ironstone that are a quarter of an inch around or bigger. The concrete at Andamooka is a conglomerate. At Koroit and Yowah nuts are often found in a conglomerate band.
A Machine designed for Lightning Ridge underground mining. It resembles a small excavator which swoops down on the mining face with a multi-pronged head. Essentially this contraption replaces the tiring hand held jackhammer.
A more or less horizontal intersection, usually clay below sandstone, which may or may not be productive for Opal.
They carry gem Opal, in the form of thin and powerful colour bars.
Mined in the Peruvian Andes this monochromatic pastel pink Opaline material is an opaque gem, without the colour-play usually associated with precious opals. The best quality stones are those without black fern-like inclusions.
It may be several inches thick and a foot long. The free pipes are found in or below the hardened layer or 
Sources & Image Credits:
A JOURNEY WITH COLOUR Vol II Part A, Len Cram, 1998.
AN OPAL TERMINOLOGY, J.S. Gunn, 1971.AUSTRALIAN PRECIOUS OPAL, Archie Kalokerinos, 1971.
BLACK OPAL FOSSILS OF LIGHTNING RIDGE, Elizabeth & Robert Smith, 1999.
LAPIDARY JOURNAL, Article: Opal in the US by June Culp Zeitner, June 1986.
OPAL - THE PHENOMENAL GEMSTONE, 2007.
OPALINE, Miners & Merchants of Opal (various photos of mining & gems)
REDISCOVER OPALS IN AUSTRALIA, Stephen Aracic, 1999.
Opal Deposits Elsewhere
Other Opal Deposits on the Globe
Common opal has been found and forms in numerous parts of the globe.
These include the deep ocean floor where dead Sea Plankton, which have the same composition as opal, are deposited.
Outside of Australia opals are predominantly volcanic in origin.
In Ancient times and up until the early 19th Century the Precious Opal on the market was mainly from the Eastern European Mines now in the Czech Republic, Slovakia & Hungary.
New South Wales Opal Towns & Fields
Lightning Ridge - 'Home of Black Opal'
Lightning Ridge – 'Home of Black Opal', the most highly prized variety in the trinity. 
The ‘Ridge’ is unrivalled, nearly all of the world’s Black Opal and the finest come from here. Over the last few decades it was the equal largest producer by value.
Originally known as the 'Wallangulla' Opal fields; Legend has it that the fitting title "Lightning Ridge" was derived after a shepherd, his dog, and six hundred sheep were killed during a fierce electrical storm, while sheltering on a low ridge in the area.
There are more than 70 Opal fields in the greater Lightning Ridge region. Opal mining occurs in three seperate areas totalling 2300 square kilometres, there are about 6000 active claims, but only 500 to 800 are mined regularly and 2000 only casually.
The main fields are the original Town fields within a 10 km radius of the PO and Coocoran 30 km to the West, the Opal here is typically found as ‘nobbies’ or nodules, their dark appearance is due to carbon (organic matter) and iron oxide trace elements. The Grawin and Glengarry fields 80 km to the SW of Lightning Ridge township produce ‘seam’ Opal similar to the dark or semi-black Opal found at Mintabie in South Australia.
The population of Lightning Ridge has proven nigh impossible to estimate at times. With production at its peak in the early 1990’s, there were more than 7,000 people in the town. Currently estimates run at 3000 permanent residents, not including numerous transient inhabitants and camp dwellers, however only 1,109 people voted in the local government elections in 2004.
Lightning Ridge receives over 80,000 visitors per year, with numerous good quality motels and several caravan parks to choose from most people usually stay a couple a days at least.
White Cliffs - 'Australia’s First Opal Town'
White Cliffs - reputedly discovered by a party of Kangaroo hunters in 1884. 'Australia’s First Opal Town' was developed after the pioneering Opal buyer and promoter Tully Wollaston bought the first parcel in 1889. White Cliffs was the jewel in the colony’s crown producing the bulk of the world's Opals for more than a quarter century. Several syndicates were floated in London; each employed hundreds of men, who worked on a tribute system.
Large amounts of stable seam opal brought a renaissance into the overseas markets in England, USA, Germany and France. Although often passed as Hungarian Opal until the turn of the twentieth century, Australian Opal was easier to value, clean and manufacture. Opal of this quality had not been seen for more than a century, thus the new Australian Opal soon gained credibility. Appreciation for the national gemstone developed and it became highly sought-after, which in turn spurned the discovery of new fields like Lightning Ridge.
White Cliffs was richly endowed with opalised fossils and is home to the ‘pineapple’, a replacement of a mineral crystal of glauberite or ikaite which is first replaced by calcite and then opalised.
In 1899 nearly two thousand people lived within two miles of the town area of White Cliffs, there were five hundred odd timber and iron houses, as well as countless 'calico mansions' fabricated from Hessian and bark, or canvas. There was an underground restaurant, bakery, and bar; however dugouts were scarce and most miners lived in mine shafts. Intense summer heat drove the first miners underground and by 1900, most residents had followed suit.
To this day eighty per cent of local residents live in dugouts and there is excellent underground accomodation a truly iconic experience not to be missed!
So go on! Get 'off the beaten track' and visit this fabulous Aussie treasure of a tourism destination, to plan your trip goto www.whitecliffsopalfield.com
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Sources & Image Credits:
BEAUTIFUL OPALS - AUSTRALIAS NATIONAL GEM - SPECIAL 2000 COMMEMORATIVE EDITION, Len Cram, 1999. Opaline, Photo collection (Agitator) ridgelightning.com, photo titled "Caravans, Rain and Lightning" by Russell Gawthorpe, 2008. P.R. Evans Collection & photography ( Red on Black cabochon) |
Blood Diamonds & Battlers
Shearers Strikes & Opal Rushes
The United Nations General Assembly recognized that conflict diamonds are a crucial factor in prolonging brutal wars in parts of Africa. Fortunately Australia is and always has been a stable country with strong labour rights.
During the Great Shearers' Strikes in the 1890s, 500 shearers camped just south of Winton in outback Queensland as the town was placed under marshal law. This was not only the beginning of the foundation of the Australian Labor Party, but an opportune time when disaffected men without work were willing to chance their luck; It is by no coincidence that Opalton, 100 kilometers further south, developed into a township soon afterwards.
Australian opals have almost always been mined by individuals, families and small partnerships. Since opal production began in earnest at the turn of the 20th Century numerous companies have floated over the years, in an attempt to become large scale producers, all have had limited long term economic success.
How 'bout some Dinkum Blood Red Opals!?
Red is the most sought after colour in gemstones, red on black opals are worth $10,000 per carat or $50,000 per gram. Although this sounds expensive - gem opals are a bargain - when you consider that a monochromatic stone such as a red ruby could set you back 10 times that and a red diamond 100 times that price!
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In search of colour - from Bendigo to the Barcoo - No matter where the early miners went the kit was much the same.
This Britton & Rey lithograph shows an extensive array of boots, hats, cooking equipment, a puddling cradle, pick and shovel and the indispensable firearms including Colt pistol.
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The 'Moussaeff' red diamond found in Brazil, 1990. Weighing 5.11 carats it is considered the largest red diamond and estimated to be worth $7m
The intense blood red displayed by this Black Opal is more ruby-like
Per carat their values are generally very similar however large rubies (≥10 carats) command a premium |
In the 1850's the Australian 'Gold Rushes' were on and toward the close of 19th century the 'Opal Rushes' began.
On the Queensland Opal fields and just south of the border at Lightning Ridge in NSW many of the first Opal gougers were shearers and station-hands who had little or no geological knowledge, they were also joined by disaffected gold diggers.
In 1895, Banjo Patterson wrote "Waltzing Matilda" - Australia's unofiicial national anthem, whilst visiting Dagworth Station 100km north-west of Winton. The Kynuna Opal fields had been discovered only 30 km west of Dagworth Homestead a year earlier.
Once a jolly swagman camped by a billabong,
Under the shade of a coolibah tree
The 'swagman' was an itinerant worker, his bed roll bundled his belongings, he likely could have specked a colourful shard or even had a dig on his foot-weary travels.
Up jumped the swagman and sprang into the billabong,
"You'll never catch me alive", said he,
And his ghost may be heard as you pass by that billabong
"You'll come a-Waltzing Matilda, with me".
Combo Waterhole, the 'billabong', where Patteron's 'swagman' met his fate is also surrounded by Opal mines. Alas the swaggie's secret spots went with him!
The diggers came from all over the globe, Irish, Anglo-Saxons, Germans or Chinese and later in the 1950-60's Europeans many of Balkan decent. Attracted by various ventures they soon found themselves struck by 'Opal Fever 'and over time Opal mining developed into a profession.
On the world's driest continent and in its driest parts where opals are found, the bush remains a harsh and often unforgiving environment. For many it has been perilous and unprofitable, having dreamt of hitting the jackpot instead to find meager traces. Others have been lucky! They were whipped by the fire in the stone - destined to be 'Opal lovers' if not lottery winners.
The excitement and romance of the early years may not have gone forever - !Eureka! is still out there on the Opal fields. In actual fact a good patch of red on black Opals could set one up for a neat lifestyle.
Australia's magnificent outback is still home to rugged individualists or 'Little Aussie Battlers' and the Opal industry survives by their sheer tenacity. No single corporation can emulate these men and women in their pursuit nor control the natural wonder that is Opal!
| Sources & Image Credits:
THE Opaline COLLECTION (Photo. Black opal) Opal Miner at his campsite, Lightning Ridge, 1911. B & W Photograph by E.C.Kempe. nla.pic-vn3801038 used with permission from the National Library of Australia P.R. Evans Collection & photography ( Red on Black) TO THE DIGGINGS, Geoff Hocking, 2000. (Lithograph) famousdiamonds.tripod.com/moussaieffreddiamond.htmlWikipedia on Banjo Patterson's famous bush ballad "Waltzing Matilda |
