Why you should buy Australian Opal We love the range of color in Australian opal . It's a very special stone that can display any color in the spectrum. We appreciate all the varieties, and carefully choose which stone will look best set in the piece its going on. The type of setting will determine the quality of stone we use; lower grade opal for silver, and the good stuff for gold or platinum settings. Opal is found in many places, including the United States, but 90% of the supply comes from Australia. Of that, 2% is boulder opal, making it the most prized and expensive. Opal is found in small supply in a few different states of the US; Idaho, Arizona, and Nevada. Mexico produces a type of transparent opal often referred to as "fire" opal that is a different class of opaque stone without the play of color you see in Australian opal. We prefer Australi...