Spectrolite, the most valued type of labradorite, comes from Finland. The name is derived from Labrador which is the main and original source of the Canadian variety of this feldspar stone. It occurs in metamorphic or igneous rocks in Labrador (Canada), Finland, Madagascar, Australia, Mexico, Norway, what used to be known as the USSR and the USA. The most spectacular rocks come from Finland and Madagascar. Spectrolite is a trade name for Labradorite found in Finland. Lesser rocks come from the USA and Mexico. The main source is Labrador, Canada for which it is named.Labradorite is a sodium rich plagioclase feldspar. It displays a particular type of iridescence on a dark to light smoke gray background. This effect is derived from a mosaic arrangement of platelets of different compositions and minute inclusions of ilmenite, rutile, and magnetite, which cause light diffraction. When light strikes Labradorite from a particular direction, it may display striking rainbow-colored reflections (violet, blue, green, yellow, orange and red) known as "Labradorescence" or "Schiller." It has been described as looking like the delicate wings of a tropical butterfly.It's main characteristic is the "Labradorescence" that makes it more valuable. It is cut into beads, gems or flat cabochons for use in jewelry. Sometimes it is carved into shapes or objects of art. It is also used as a flat ornamental material in decorative boxes or for engraving.The light that hits labradorite stone will emit a rainbow of colors as the various portions of the stone reflect light in different ways. If you have ever seen the rainbow colors in a small oil spill, you will recognize the colors in the labradorite stone. There is a metallic look to labradorite which gives it a very unique look.