- 90% of the world supply of opal comes from Australia.
- Opal is also found in Mexico, Ethiopia and Indonesia.
There are three generic types of Australian opal; black opal, white opal and boulder opal.
Black Opal is found in Lightning Ridge and White Cliffs, New South Wales. Black Opal is precious opal found in black common opal and characteristically presents in dark colours as a result of being hosted by black common opal. Black Opal is found in pockets in clay beds in the form of nuggets or “nobbies” and also as seams.
White Opal is found in Coober Pedy, South Australia. White Opal is precious opal found in white common opal and characteristically presents in lighter colours than the black opal as a result of being hosted by white common opal.
Boulder Opal is found in Queensland, Australia. Boulder Opal is a unique type of natural opal that forms within sandstone and ironstone boulders. The two main fields where Boulder Opal is mined are located near and around the towns of Winton and Quilpie. Other important deposits of boulder opal occur in the areas surrounding the townships of Yowah and Koriot near Cunnamulla. The Queensland Boulder Opal fields cover an area of many thousands of square kilometers (Ratliff, 2014).