Labradorite

Labradorite is no longer valid as andesine today as an independent mineral, but is a plagioclase, a relatively frequently occurring mineral mixture of albite and anorthite from the group of the feldspars and the mineral class of silicates. Anorthite is defined to be 50 to 70% ( An50 -70).

Special Features

Striking is the iridescent labradorite the play of colors in metallic gloss, the so-called labradorescence (verb: labradorisieren ), which is caused by interference and reflection of light at the submicroscopic exsolution lamellae. This shimmer is predominantly blue, purple and green, but occasionally found in other colors.

Etymology and history

Labradorite is named after its first location, the Labrador peninsula, named. On the coast of which he was discovered in 1770 by the Czech missionary Father Adolf.

Spektrolith was first described in 1896 in the book Gemology by Max Bauer. He received his name but by the Finnish professor Aarne Laitakari for its iridescence in all colors of the spectrum.

Varieties

As a Labradorite Spectrolite from Ylämaa in Finland is called, is characterized by the full color spectrum of labradorescence.

Madagascar moonstone or Rainbow Moonstone, however, is the trade name for a white, almost transparent labradorite with rich blue surface Schiller, who is often used as an imitation of the genuine moonstone.

Education and Locations

Labradorite is either formed magmatic in dunite, gabbro, basalt and anorthosite or metamorphic in amphibolite.

Important sites are Quebec and Nain in Labrador / Canada, the Korostanskiymassiv in Ukraine, Ylämaa in Finland, area around Larvik in Norway and Madagascar.

Use as a gemstone

Labradorite is often processed into semi-precious stones, due to its beautiful luster. Its high sensitivity to any influence of heat, acids and alkalis as well as electroplating baths makes processing difficult. Even an ultrasonic cleaning will damage the stone.