The prospector is guided in his search by a knowledge of the geological conditions under which useful minerals occur
Australian Opal Fields
The following information is a brief outline of opal fields/towns of ‘major opal occurrence’ in the area around the Artesian basin – bordering on the three states of NSW, SA, QLD where these opal townships and surrounding opal fields are located.
South Australia (SA) Opal fields
By weight SA produces most of Australia’s opal. Fields such Coober Pedy, Andamooka, Mintabie, and Lambina produce stunning White and Crystal Opals.
ANDAMOOKA (SA) known for Matrix Opal. One can also find burried in Andamooka and surrounding fields top gem, crystal, light opal (and some dark opal – not the true dark opal of Lightning Ridge). Good quality seam gem opal, jelly and crystal, milky as well as grey and light opal is found in Andamooka and surrounds. Also found are matrix rock and painted ladies.
COOBER PEDY (SA) Known as the Opal capital of the world and famous for two types of quality white opal – crystal & milky opal. Australia provides 95% of the world’s supply of commercial opal and for decades it was considered that the largest percentage of Opal on the world market came from the fields around Coober Pedy.
MINTABIE (SA) this area is most famous for the extraordinary crystal opals. In the 1980’s, the area was the largest opal producer by value.
New South Wales (NSW) Opal fields
The Black Opal was proclaimed the State gemstone of NSW in 2008. It is the most rare and valuable type of opal. New South Wales produces the largest amount of Australian opal by value.
LIGHTNING RIDGE (NSW) famously known for the world renowned Black Opal. First discovered in around 1895, with the first mine shaft being sunk in 1904, shortly after came the first Opal Rush. Lightning Ridge has produced some of the finest opal ever found.
WHITE CLIFFS (NSW) known for Crystal Opal. White Cliffs is Australia’s oldest commercial opal field.It’s one of just a few places in the world where white opal is found and is most famous for its rare ‘pineapple’ opals with their distinctive spiky shape.
TINTENBAR (NSW) these pretty opals of volcanic origin formed in cavities of basalt rock. The jet black opal is opaque, rich flashes of deep red, orange, golden green and blue are displayed throughout the body of the stone. Some of the opal is colourful watery jelly, crystal and grey to semi-black. Not considered viably commercial as descriptions can include cracky and unstable.
Queensland (QLD) Opal fields
Queensland produces the stunningly interesting and unique boulder opal. The opal is found attached to an ironstone host rock. Unique to Queensland, the opal occurs in deposits in weathered sedimentary Cretaceous rocks. The Queensland opal fields are within a belt of deeply weathered Cretaceous sedimentary rocks known as the Winton Formation, which extends in a north-westerly direction from the New South Wales border at Hungerford stretching west of Cunnamulla, Quilpie, Longreach and Winton to Kynuna, a distance of about 1000 km.
OPALTON (QLD) is one of the largest opal fields in Queensland and is known for the quality of opal mined. In 1899, the largest piece of pipe opal ever recorded was discovered at Opalton – it was over 10 feet (3m) long and rumored to be as thick as a man’s leg!
QUILPIE (QLD) is the outback mining town ‘home of the great Boulder Opal’. The town services surrounding opal fields.
YOWAH (QLD) known for the famous Yowah nut opal. Close to Yowah are the Koroit and Black Gate opal fields. Opal is fond in nut formation and ironstone matrix. Beautiful intricate designs in nut opal are found in Yowah and throughout the four mile area and Black Gate. Pipe opal, nuts and ironstone matrix nut opal vary in size.
Western Australia (WA) Opal
COOLGARDIE (WA) Better known for it’s gold mines, WA opal, first discovered in 1904 is similar in structure to Qld boulder opal, or Tintenbar opal . Miners extract the precious black opal vein-lets transecting graphite-chlorite schist. The veins of potch are usually much wider than the precious variety. Glassy and bluish in color due to the schist background. Most of it is thin seam opal. The opal is brilliant in sunlight or shade showing dazzling colors of red, orange, green and blue, in a pattern of medium to fine. Rock impurities show through some of the medium grade stones and still looks beautiful. But gem opal on black basalt rock backing, that is free from impurities is classed as top quality opal.
Other States of Australia
Opal has been found in other states of Australia, generally considered common opal and not mined commercially. Opal has been found in the Northern Territory, north of Tennant Creek in Helen Springs as well as Victoria near Beechworth, Sassafras Creek and Gelantipy. Common variety’s of opal have also been found in Tasmania.
Reference: Aracic S, 1999, Redisocer Opals in Australia, Kingswood Press Pty Ltd, Qld Australia
What is an old prospector?
A prospector is someone looking for mineral deposits. Prospectors are usually after opal & gold. A prospector is a type of explorer, but one with a specific purpose: prospectors are after mineral deposits. Mineral deposits are found in the ground, so prospectors will commonly be looking down.vocabulary dictionary