Labradorite

Labradorite is a plagioclase feldspar, an intermediate member of the albite–anorthite series with an albite : anorthite ratio of about 30 : 70 to 50 : 50. Its body color is usually gray, brown or black, and many pieces show labradorescence, a play of blue, green, gold or other colors seen from certain angles. It is a common mineral in rocks such as gabbro, basalt and anorthosite, and is named after Labrador, Canada.