Boulder Opal

Outback Dream

 

Boulder Opals are a particularly popular Australian Opal variety. The main mining areas of the Boulder Opals are in Queensland in a 300 km wide and 800 km long belt of weathered Cretaceous sediments, mainly in the areas around Winton, Vergemont, Jundah, Quilpie, Eromanga, Yowah and Cunnamulla.

With luck, effort and perseverance you will find valuable Opal in an iron-clay mixture called sandstone boulders - with a size of a few centimeters to several meters. Inside the boulders, millions of years ago, the once fluid and colorful Opal has flowed into the natural cavities, cracks, crevices and tubes in the host rock. In these remote outback mining areas, where the opal deposits are widely scattered, the Boulder Opal is primarily mined in open cuts with the use of heavy machinery.