I have for sale a Large and sliced in half Koroit Opal Rough Nut. This one weighs 2779.5cts or 555.9 Grams, (both pieces together) Over half a Kilo. These are Ironstones Brown/Red colour with a skin over the top, and a rougher/pittier base. There is a Nut at one end joined to the main one, both together with a Skin over the top of the whole thing. It has Blue/Green Fires showing along and through the skin, showing a band of Pattern/Colour, also some Blue/Purple and Greens within the core/nut section itself.  Superb specimen set for someone, or slice and cut it up into multiple stones/cabs, or 2 larger specimen pieces. There is a few natural fault lines in places.  Thanks for looking. ,