Labradorite (a variety of plagioclase feldspar) is a fairly abundant grayish mineral that has brilliant flashes of color (usually green, blue or red) after it is polished (called labradorescence). The crystals are transparent to translucent. There is a darker variety of labradorite (called "black moonstone") which has bluish inclusions. Labradorite is usually cut with a flat surface in order to highlight the flashes of color. Labradorite was originally found along the coast of Labrador about 1805; it is also found in Newfoundland, other parts of Canada, also known as spectrolite, the Ukraine, the Ural mountains, and the USA.