Boulder Opal is unique among gemstones with its intense flashes of colour formed over 100 million years ago from hydrated silica embedded in ironstone. Opal comes from the Greek word 'opallus' which loosely translates as 'changing color'. Australia is the world's only source for boulder opals, with boulder opals making up only 2% of its entire opal output. As each opal is unique in color and shape boulder opals are usually cut flat or in cabochon with the natural ironstone backing intact.
A stone of strength, boulder opal is said to calm the inner soul, give clarity and aid in circulation.