I recently designed a custom piece using a recycled boulder opal.
All the opals I’ve ever encountered were each so unique, no two alike. That got me intrigued about the varying types. There are three major types of opal: Boulder Opal, Black Opal, and White Opal. They’re all found in Australia, which happens to be the producer of 95% of the world’s opal supply.
Black opals are the most valuable and white opals are the most common. Boulder opals are the rarest, only making up about 2% of Australia’s opals. First discovered in the 1870’s, boulder opals are so named because they’re found inside of large ironstone boulders. They’re easily distinguished by the layer of solid brown ironstone left on the back of the stone. The ironstone enhances the durability and vibrant color, usually increasing the opalescence as well. Opalescence is typically a milky, whitish blue color, but can be found in other colors as well.
Boulder opal can be found in a range of colors, the most common being: blue, green, yellow and orange. High quality stones can contain all colors of the rainbow in a single stone. However, the primary body color is usually a dull brown, gray or black.
Due to the ironstone matrix, boulder opals have a much higher density than other types. This means, boulder opal gems are much smaller compared to common opals of the same weight. Boulder opal is often cut in irregular, free-form shapes, to maximize the size and value of the gemstone. Take a look at this gorgeous, modern beauty!
CED custom boulder opal pendant
