What is a Coober Pedy opal stone ?

A Coober Pedy opal stone is an opal stone that has been mined in Coober Pedy, a vast opal field in South Australia.

Coober Pedy produces over 90% of all precious opal stone mined in the world (mostly white opal but also beautiful light and crystal opal).
It is the main source of opal stone used to make Australian opal doublet stones and opal triplet stones.
When cut and polished, a solid Coober Pedy opal stone is by world standards, a "Natural opal, Type 1".