Labradorite is a member of the feldspar group of minerals. It is one of the intermediate minerals in the solid solution between Albite (NaAlSi3O8) and Anotrhite (CaAl2Si2O8). To be considered labradorite, the feldspar must have at least 50-70% calcium and no more than 30-50% sodium in its makeup. Labradorite dispays a property called labradorescence, a blue/green play of color when the light strikes it at the correct angle. This shimmer of color is caused by internal refraction of the lightwaves changing their wavelength and thus their color.
| Ca(50-70%) Na(50-30%)(Al, Si)AlSi2O8 |
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| Tectosilicate |
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| Triclinic |
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| -1 |
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| 6-6.5 |
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| 2.7-2.74 |
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| {001} perfect, {010} good, {110} distinct |
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| Conchoidal |
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| Gray with blue/green play of color |
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| White |
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| Vitreous, dull |
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| Transparent/translucent |
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| Granular, striated |
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| Shimmery blue play of color called Labradorescence |
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| Notable Localities: |
Labrador, Canada |
| Uses: |
Polished as a gem and decorative stone |
Specimens:
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