Boulder rough opal sellers take picture of the boulder rough dipped in water so the image will expose the colours of the stone as if it was polished. Buyer will receive the boulder or Koroit opal rough in a dry condition.
Boulder opal Rough is mined in Queensland Australia.
It is formed as veins in ironstone. Ironstone is the deep brown potch like stone that is very strong.
Most popular opal mining towns are Quilpie and Winton and many old fields like Jundah or Hammonds mine still produce opal.
Boulder opal mining is capital expensive with large bulldozers and excavators..D9…