The fields of boulder opal extend throughout most of southern Queensland, from Hubgerford to Winton. Most of the mining activity occurs around Quilpie, in the south, and Opalton, near the center of Queensland.

Boulder opal is famous for its color intensity. No othr opal type can match the size and vibrancy of the color spots that are visible when the piece is held at angles to catch the play of fire.

In adition, the three-dimensions of boulder opal make it easier for jewelry designers to do some unique things with their jewelry. Matched earrings are particularly popular. “Splits” – a boulder opal split in two so that one half is a mirror image of the other half, are as rare as matched emeralds, rubies or colored diamonds…and their prices reflect this.

Boulder opal is also renowned for its durability. Because water content of boulder opal is low, it almost never cracks or crazes as the years go by.