Large Rough/Sliced Koroit Opal Half Nut Specimen 685cts Purple/Blue Fires Qld Au

I have for sale a Large and Chunky Half Koroit Opal Nut from Queensland Australia. This one weighs 685cts and is 74x66x28mm..  Ironstone base with a large main Nut through the piece. Fine koroit Patterns, and lots of Fine Blue/Purple Fires through the stone. The Nut/Pattern is showing at one end where the outer skin has fallen away. Will skin over a huge Specimen Cab/Freeform, or keep as it is, or slice it into maybe 4 slices all with this pattern through .,,. Thanks for looking,.,.,.