The finest opal ever unearthed

Virgin rainbow opal

The Virgin Rainbow opal is worth more than $1 million and is regarded as the finest opal ever unearthed. Just over 6 cms long, it weighs 72 carats and features brilliant colours, from orange through to violet. The stone was found in 2003 at Coober Pedy, in South Australia’s mid-north, a region which produces about 90 per cent of the world’s opals. Opals are unique among gemstones in that they are not technically minerals, but mineraloids, meaning they don’t generally occur in a uniform crystalline structure. The gems are formed out of a mix of water and silica which form a gel that eventually hardens into an opal