Labradorite
Variety of anorthite
Uncommon · (Ca,Na)(Al,Si)₄O₈
A feldspar that displays labradorescence, an iridescent play of colour caused by light interference between thin alternating layers of different compositions within the crystal. Common in basaltic igneous rocks.
Identity
- Formula
- (Ca,Na)(Al,Si)₄O₈
- Chemical class
- Silicate
- Mineral group
- Albite, Moonstone, Orthoclase, Sunstone
- Also known as
- Spectrolite (Finnish trade name), Rainbow moonstone (trade name for Madagascar labradorite)
Crystallography
- Crystal system
- Triclinic
- Habits
- Tabular, Massive
- Fracture
- Uneven
Physical properties
- Mohs hardness
- 6.5
- Density
- 2.7 g/cm³
- Luster
- Vitreous, Pearly
- Colors
- gray, brown, green, blue, yellow, colorless
- Streak
- white
- Transparency
- Transparent, Translucent
Geology
- Origins
- Igneous, Metamorphic
- Host rocks
- Granite, Volcanic rock
- Associated minerals
- pyroxene, Olivine, Magnetite
- Geography
- Canada (Labrador), Finland, Madagascar, Norway, USA, Mexico
Classification
- Rarity
- Uncommon
- Gem quality
- Yes
Arcane properties
- Affinity
- Arcane, Illusion
- Effects
- Illusion, Mind
- Planar origin
- Material Plane
Sources
- Labradorite. Mindat.org (Hudson Institute of Mineralogy).
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Labradorite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Labradorite. Gemdat.org (Hudson Institute of Mineralogy).
- Moonstone Description. Gemological Institute of America, Gem Encyclopedia.
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