Learn about the fascinating world of Australian opals, prized gemstones that have captivated humans for thousands of years. Australia produces approximately 95% of the world's precious opals, with Coober Pedy being the largest producing region.
Opals form over millions of years when silica-rich water seeps into cracks and voids in rock formations. As the water evaporates, it leaves behind tiny spheres of silica that stack in regular patterns. When light enters the opal, it diffracts through these spheres, creating the spectacular "play of color" that makes opals unique among gemstones.
Australian opals come in several varieties. Light opals have a white or light body color and are the most common type found in Coober Pedy. Crystal opals are transparent to semi-transparent with vivid play of color. Black opals, primarily from Lightning Ridge, have a dark body tone that makes colors appear more vivid. Boulder opals from Queensland form in ironstone and often display brilliant patterns.
When evaluating opal quality, experts consider several factors: brightness of color play, pattern type and uniformity, body tone, and transparency. Rare patterns like harlequin, flagstone, and rolling flash command premium prices. The most valuable opals display bright, broad color patterns visible from multiple angles.
Coober Pedy opals are renowned for their bright colors and excellent clarity. The unique geological conditions of the region, including ancient inland seas and perfect silica concentrations, created ideal opal-forming environments found nowhere else on Earth.