Labradorite is a flashy stone. Its base color is usually gray, and when you turn it around, it displays flashes of other colors - such as blue, green, yellow, pink, purple, orange. Sometimes there will only be one color flash - but there can be more than one, too.  It occurs as clear, white to gray, blocky to lath shaped grains in common mafic igneous rocks such as basalt and gabbro, as well as in anorthosites. The geological type area for labradorite is Paul's Island near the town of Nain in Labrador, Canada. It occurs in large crystal masses in anorthosite and shows an iridescence or play of colors. The iridescence is the result of light refracting within perthitic lamellar intergrowths resulting from phase exsolution on cooling. Gemstone varieties of labradorite exhibiting a high degree of iridescence are called spectrolite; moonstone and sunstone are also commonly used terms, and high-quality samples with good iridescent qualities are desired for jewelry.