Chemical Composition: Na(AlSi3O8 Ca(Al2Si2O8) (Sodium Calcium Aluminium Silicate)
Mohs' Hardness: 6-6.5
Specific Gravity: 2.69-2.70
Cleavage: Perfect
Refractive Index: 1.560-1.568
Double Refraction: +0.008
Dispersion: None

A type of the albite-anorthite series of plagioclase feldspars, Labradorite was discovered in the year 1770 in the Candian peninsula, Labrador. While not the most expensive of stones, labradorite does have some properties that make it one of the more unusual of rocks. While it is often colored black, or a dark ashen hue, labradorite explodes with color when it is rotated in place, providing there is a good light source near by. Greens or blues, sometimes even yellows and pinks, slink their way over the stone as it spins. The shining color when the stone is turned is called labradorescence, after this stone which shows it better than any other stone. This aspect alone makes labradorite a very nice stone for jewelry.

Labradorite is found in plutonic and volcanic igenous rocks. Some specimens have also been discovered in some metamorphic rocks as well. The easiest way to tell whether an unknown stone is labradorite or not is to slowly spin it, checking for any labradorescence. The best specimens of labradorite come from the Labrador Peninsula and the province of Newfoundland, both in Canada. However, labradorite can be found all over the world. Finland, the Malagasay Republic, Mexico, Madagascar, Russia as well as some northern US states all have deposits of labradorite. The labradorite found in those locations all appears as irregular masses. So far, the only labradorite to be found in a crystalline structure has been from Western Australia.

According to an Inuit legend, the Aurora Borealis, better known as the Northern Lights, were once imprisoned in the rocks along the coast of Labrador. A wandering Eskimo warrior saw the trapped lights and tried to free them by striking the rocks with his spear. Most of the light escaped into the sky, but some still remained trapped in the rocks, which are, of course, now called labradorite.

Precious Stones, by Dr. Max Bauer. Charles E. Tuttle Company: Rutland Vermont and Tokyo, Japan, 1969
Gemstones of the World, by Walter Schumann. Sterling Publishing Co., New York, 1979
Simon and Schuster's guide to Rocks and Minerals, Simon and Schuster Inc. New York, 1978

Lab"ra*dor`ite (), n. Min.

A kind of feldspar commonly showing a beautiful play of colors, and hence much used for ornamental purposes. The finest specimens come from Labrador. See Feldspar.


© Webster 1913.

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