English
Image:Labradoryt, Madagaskar.JPG|thumb|Labradorite
Etymology
Named for the type locality in Labrador.
Noun
labradorite (plural: labradorites)
- mineralogy A plagioclase feldspar, the fourth member of the Albite-Anorthite solid solution series. Often very coarsely crystalline, it is used as a decorative stone for carvings and building façades. Crystal surfaces often show a bluish reflection called "Schiller", which resembles the reflections from a butterfly's wing.
Chemical composition: Calcium sodium aluminum silicate, <math>Ca_xNa_xAlSi_3O_8</math>
Physical properties:
*Moh's Hardness: 6.0
*Specific gravity: 2.71
*Color: Usually bluish-gray to dark gray
*Luster: glassy
*Fracture: conchoidal
*Cleavage: two good at about 94º to each other
*Habit: Triclinic - pinacoidal. Crystals are common and usually striated.
Related terms
:See Rock, Feldspar, Plagioclase
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