Input interpretation
anorthite (mineral) | epistolite (mineral)
Images
Images
General properties
| anorthite | epistolite alternate names | ab0 | amphodelite | anorthoîte | anortite | barsovite | beffanite | beffonite | biotine | calciclase | calcium feldspar | christianite | cyclopite | didymolite | indianite | latrobite | lepolite | lime-feldspar | thiorsauite | plagioclase (An90-100) | (none) formula | CaAl_2Si_2O_8 | Na_4Nb_2Ti(Si_2O_7)_2O_2(OH)_2·4(H_2O) discovery year | 1823 | 1900
Basic properties
| anorthite | epistolite density | 2.735 g/cm^3 | 2.77 g/cm^3 transparency | transparent | subtransparent | translucent | translucent birefringence | 0.0115 | 0.072 luster | vitreous | silky | pearly Mohs hardness | 6.25 | 1.25 tenacity | brittle | streak | white | white magnetism | nonmagnetic | nonmagnetic color | colorless | gray | white | red | reddish gray | white | yellowish white | gray | light brown fracture | uneven | brittle molar mass | 277.4 g/mol | 758.2 g/mol
Units
Mineral identifiers
| anorthite | epistolite Strunz ID | VIII/J.07-70 | VIII/C.14-50 Dana ID | 76.1.3.6 | 56.2.7.1
Crystallographic properties
| anorthite | epistolite crystal system | triclinic | triclinic crystal class | 1 | 1 unit cell volume | 1340 Å^3 (cubic ångströms) | 455.6 Å^3 (cubic ångströms) d-spacing | 3.2 Å (ångströms) | 3.18 Å (ångströms) | 4.04 Å (ångströms) | 4.33 Å (ångströms) | 6.11 Å (ångströms) | 2.72 Å (ångströms) intensity | 100% | 75% | 60% | 100% | 100% | 80% molecules per unit cell | 8 molecules per cell | 1 molecule per cell 2V angle | 13 π/30 radians≈78° (degrees) | 7 π/18 radians≈70° (degrees) refractive indices | 1.574 | 1.581 | 1.586 | 0 | 0 | 0 | 1.61 | 0 | 0 | 0 | 0 | 0 dispersion | weak | strong unit cell lengths | 8.177 Å (ångströms) | 12.88 Å (ångströms) | 14.17 Å (ångströms) | 5.46 Å (ångströms) | 7.17 Å (ångströms) | 12.04 Å (ångströms) unit cell angles | 93.17° (degrees) | 115.9° (degrees) | 91.22° (degrees) | 103.6° (degrees) | 96.01° (degrees) | 89.98° (degrees)
Wikipedia summary
Anorthite
Anorthite is the calcium endmember of the plagioclase feldspar mineral series. The chemical formula of pure anorthite is CaAl_2Si_2O_8. Anorthite is found in mafic igneous rocks. Anorthite is rare on the Earth but abundant on the Moon.