2 Nice Sliced/Rough Koroit opals 437.8cts Queensland Australia Nuts/Pattern/FiresI have for sale 2 Nice Rough Sliced Koroit Opals from Queensland Australia. These weigh 437. 8cts in total. Ironstone base material with Patterns through them and Fires mixed into them aswell. One is a Double sided Slice, Concentric Rings with Patterns throughout. Thinner piece, second is the end half of a Chunk Nut sat in a skin. it has patterns, some Green Fires and there is also colour poking out the skin aswell. Should clean up well once worked