This is a "Coober Pedy Opal" named for the town in Australia where these opals are mined.  The tan white you see is the stone matrix, with the beautiful purple, teal, blue, green, red and yellow opal showing through in lines of lightning and a shimmer of sparkle in many different ways.  It is one of the hottest new types of opals coming on the market, and we were among the first to carry it!  Purchased directly from the miners in Aussieland.