List of minerals by optical properties
Appearance
Name | Crystal system | Indicatrix | Optical sign | Birefringence | Color in plain polars |
---|---|---|---|---|---|
Anorthite | Triclinic | Biaxial | (-) | 0.013 | None |
Biotite | Monoclinic | Biaxial | (-) | 0.045 | Brown |
Calcite | Hexagonal | Uniaxial | (-) | 1.486 | None |
Chlorite | Monoclinic triclinic | Biaxial | (-) or (+) | 0.011 | Pale green |
Cinnabar | Trigonal | Uniaxial | (+) | 0.351 | None |
Corundum | Trigonal | Uniaxial | (-) | 0.09 | None |
Cristobalite | Tetragonal (pseudoisometric) | Uniaxial | (-) | 0.003 | None |
Enstatite | Orthorhombic | Biaxial | (+) | 0.011 | None |
Epidote | Monoclinic | Biaxial | (-) | 0.046 | None |
Garnet | Cubic | None (isotropic) | N/A | N/A | None |
Glauconite | Monoclinic | Biaxial | (-) | 0.032 | Light blue |
Glaucophane | Monoclinic | Biaxial | (-) | 0.021 | Pleochroic blue |
Microcline | Triclinic | Biaxial | (-) | 0.010 | None |
Muscovite | Monoclinic | Biaxial | (-) | 0.042 | None |
Olivine | Orthorhombic | Biaxial | (-) or (+) | 0.042 | Colorless to pale green |
Orthoclase | Monoclinic | Biaxial | (-) | 0.005 | None |
Quartz (α) | Hexagonal (trigonal) | Uniaxial | (+) | 0.009 | None |
Sanidine | Monoclinic | Biaxial | (-) | 0.007 | None |
Talc | Triclinic | Biaxial | (-) | 0.051 | None |