The boulder opal excels in incredibly rich to wild colors, an exciting color play, and an unrivaled variety of color patterns. It occurs in irregular, wobbly and undulating veins in ferrous sandstone, or forms impregnation.
The first occurrences and finds of expensive opals in Australia date back to the end of the 19th century, while their mining began only in the twentieth century. The production of Australian precious opal mining has very quickly and significantly affected the world market of this commodity until now. Australian precious opals have gained a special position and have become an internationally recognized symbol of quality and appreciation in the industry.