Tag Archives: Opal

What is a Boulder Opal? | Guide to Australian Opals | Cosmopolitan Jewellers

OpalBy cosmo June 23, 2026

Boulder opal is one of the most distinctive and sought-after gemstones found in Queensland. Known for its vivid flashes of blue, green, and sometimes fiery orange, it is prized for its natural beauty and one-of-a-kind patterns. Unlike other opals, boulder opal forms within ironstone rock. This means the opal is still attached to its natural…

Black Opal, Boulder Opal and White Opal deposits in Australia

OpalBy cosmo October 30, 2022

Australia’s Great Artesian Basin (GSB) hosts widespread deposits of Opal, and continue to be the major source of high-quality gem opal for the international coloured gemstone market. Opal mining in the GAB has produce billions of dollars’ worth of exquisite gems, including light opal mainly found in the opal fields of South Australia, Boulder Opal…