I have for sale a Huge and Gemmy Koroit Opal Rubbed/Rough Specimen from Queensland Australia. This one weighs a hefty 2170cts or 434Grams and is 100x74x39mm.  Ironstone base, part of a Huge Nut, top skin has been rubbed to show loads of Patterns and some Nice Fires in places. MIxed Blue/Purple and Green/Blues. There is some pitting in the middle of the piece. The outer skin /pattern on this is huge, with many options for cutting lots of cabs from it. The middle also has at least 2 Blue/Purple skins to clean up if its sliced up. I would clean up the top and Polish it as a massive cabinet specimen., Stones like this rarely come up for sale. One of a kind masterpiece of nature right here.    Thanks for looking.