Anorthoclase
Anorthoclase is named from Greek "an" - not, plus "orthos" - right, plus "klan" - to break, alluding to the fact that the cleavages are not at right angles.
Anorthoclase forms opaque to translucent , rarely transparent, colorless, also white, pale creamy yellow, occasionally greenish or pink, red crystals.
Anorthoclase forms opaque to translucent , rarely transparent, colorless, also white, pale creamy yellow, occasionally greenish or pink, red crystals.
| General Information | ||||||||||
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| Chemical Formula |
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| Physical Properties of Anorthoclase | ||||||||||
| Mohs Hardness | 6 to 6.5, Gems, Sixth Edition (2006) | |||||||||
| Specific Gravity | 2.56 to 2.62, Gems, Sixth Edition (2006) | |||||||||
| Cleavage Quality | Perfect,Good, Gems, Sixth Edition (2006) Perfect to good | |||||||||
| Parting | Prismatic, Gems, Sixth Edition (2006) | |||||||||
| Fracture | Uneven,Conchoidal, Gems, Sixth Edition (2006) | |||||||||
| Optical Properties of Anorthoclase | ||||||||||
| Refractive Index | 1.518 to 1.534, Gems, Sixth Edition (2006) Alpha 1.518–1.527; beta 1.522–1.532; gamma 1.522–1.534 | |||||||||
| Optical Character | Biaxial/-, Gems, Sixth Edition (2006) | |||||||||
| Birefringence | 0.006 to 0.008, Gems, Sixth Edition (2006) | |||||||||
| Pleochroism | Weak, Gems, Sixth Edition (2006) | |||||||||
| Dispersion | Weak, Gems, Sixth Edition (2006) | |||||||||
| Colour | ||||||||||
| Colour (General) | Colorless, also white, pale creamy yellow, occasionally greenish or pink, red., Gems, Sixth Edition (2006) | |||||||||
| Transparency | Translucent,Opaque, Gems, Sixth Edition (2006) Rarely transparent | |||||||||
| Lustre | Vitreous,Pearly, Gems, Sixth Edition (2006) May be pearly on cleavages | |||||||||
| Crystallography of Anorthoclase | ||||||||||
| Crystal System | Monoclinic, Gems, Sixth Edition (2006) | |||||||||
| Geological Environment | ||||||||||
| Where found: | As phenocrysts in high-temperature volcanic rocks such as trachytes, phonolites and andesites and in tuffs., Gems, Sixth Edition (2006) | |||||||||
| Further Information | ||||||||||
| Mineral information: | Anorthoclase information at mindat.org | |||||||||