The archetypal asteria is the star sapphire, generally corundum with near uniform impurities which is bluish-grey and milky or opalescent, which when lit has a star of six rays. In the red instance stellate reflection is rarer; the star-ruby occasionally found with the star-sapphire in Sri Lanka is among the most valued of "fancy stones". Other examples are star-topaz and certain prized chatoyant [ʃatwɑjɑ̃] (lit. cat's eye) chrysoberyl stones, particularly of the cymophane (yellow) variety.