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. 42mm x 33mm x 27mm, of 189.40 carats and weighs 37.87 grams. The next is approx. 42mm x 26mm x 6mm, of 96.20 carats and weighs 19.23 grams. The last piece is approx. 32mm by 25mm by 20mm, of 23.24 carats and weighs 23.24 grams. Giving a total of 401.95 carats and 80.34 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.