A small typical piece of Koroit material. The face has been polished by the miner ( not a gem grade finish) You could try cutting this into a stone. The opal in this piece is a matrix type of stone with pin fire red greens and blue fine ribbons of colour
Total Weight: 43g
Dimensions: 46 x 31 mm (approx)
Mined From: Queensland, Koroit/Yowah district