3 Nice Cut/Polished Koroit/Yowah Opal Ring Stones 17.5cts Multicolour Fires Qld AustraliaI have for sale 3 Nice Koroit Yowah Opals from Queensland Australia. These weigh 17. 5cts in total. They are all Ironstone Nuts, 2 from Koroit, NIce High dome Blue Green Veins, and the flatter Oval with Multicolour Red Blue Gold Greens all through it. The last is a Yowah Nut, Blue Green Pinfires in White Milky Opal. All 3 will make Great ring stones or similar. Great Fires to look at and work with. Thanks for looking.