Nice Large Rough/Sliced Koroit Opal Specimen 498.5cts Blue/Purple Fires Australia

I have for sale a Nice Large Rough/Sliced Koroit Opal Specimen from Queensland Australia. this one is 498.5cts and  71x68x20mm,.,. It has many Nuts/sections crammed into this one rock. Lots of Purple/Blue Fires/Thin Veins mixed through the patterns in this piece. Some Fuller nuts, some part nuts, all interesting sections to look at,. This is thicker in the middle, and gets thinner towards the edges, Excellent Large Specimen. Maybe polish the front face and keep as it is, or slice it up and see what comes out of it. Thanks for looking,.,.,.