For their lively light-play and rainbow colors, opals are unlike any other gemstone. One of four so-called phenomenal gemstones, opals exhibit a unique light interaction called opalescence, created by perfectly ordered spheres of silica, which diffract light with a magical flourish. The gem has strong ties to the continent of Australia. Throughout the 20th century, upwards of 95% of all opal was mined in Australia. In 1994, however, a dazzling discovery revealed opals of magnificent beauty in Ethiopia, a location never before known for opal deposits. The initial discovery was modest in size, but subsequent Ethiopian opal finds in 2008 and 2013 were delightfully abundant, challenging Australia’s nearly century-long dominance of the opal market.