Not many gemstones can match the stunning beauty of natural Boulder Opal from Queensland, Australia.

Boulder opal is one of the most valuable varieties of opal, second only to Australia’s black opal. Fine specimens of boulder opal can exhibit all of the spectral colors through their distinct play of color. Boulder opal may be considered to be less valuable than black opal, but it is actually much rarer. Boulder opal accounts for approximately 2% of all of Australia’s opal, however, black opal equates to around 8% of the entire yield. The remaining 90% is common opal, often referred to as ‘potch’ or ‘white opal’. Australia produces over 95% of the world’s entire supply of opal gemstones, clearly establishing it as the world’s leading opal supplier. Boulder opal was first discovered in Quilpe, Western Australia, around the year 1870. Almost all boulder opal available today is from Western Queensland’s opal-rich fields, confined to an area of about 200 to 300 square kilometers.
Boulder opal is found embedded in large boulders of ironstone, which is how it earned its name. Occurring as pebble rock, precious opal develops within thin veins, fissures and hollows. As opal miners attempt to remove the embedded opal from the ironstone, some of the host matrix is preserved during the process. For this reason, boulder opal is sometimes referred to as ‘opal in matrix’. The ironstone matrix enhances the stones durability and vibrancy of color, often increasing the desirable effects of ‘play of color’ and ‘opalescence’, which are two different optical phenomenon, commonly mistaken for being one and the same.