This is a boulder opal split, there are 2 piece’s
Boulder opal is found sparsely distributed over a wide area of Queensland Australia, sandstone or ironstone boulder country where the opal fills cracks and crevices in the ironstone boulders. Opal bearing boulder is always cut including the host ironstone. Boulder opal is in very high demand and extremely precious. Boulder opal is usually cut to the contours of the opal vein creating a baroque wavy surface and is often freeform and irregular in shape, making boulder opal unique and exclusive among it’s peers. In boulder opal there is a colour and pattern to suit everyone’s taste, from the brightest flashing red through to electric blues, greens, orange, pink, purple and many more in every shade you could imagine (every colour of the spectrum).