List of minerals by optical properties

+ Optical properties of common minerals 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 NoneCorundum 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

See also List of minerals

References