This is a mixed lot of 3 x large rough natural matrix boulder opal pieces from the mines of Queensland, Australia.
The largest piece is approx. 55mm x 37mm x 30mm, of 345.45 carats and weighs 69.08 grams. The next is approx. 62mm x 52mm x 15mm, of 311.05 carats and weighs 62.20 grams. The last piece is approx. 30mm by 26mm by 22mm, of 94.25 carats and weighs 18.84 grams. Giving a total of 750.75 carats and 150.12 grams.
These opal pieces are basically as found and have opal crystal mixed in with the natural rich brown ironstone backing. These pieces are not really suitable for jewellery unless cut, shaped and polished and should be considered unusual mineral samples in their current state.