List of minerals by optical properties

Optical properties of common minerals

Name	Crystal system	Indicatrix	Optical sign	Birefringence	Color in Plain Polar
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	Orthorombic	Biaxial	(+)	0.011	None
Epidote	Monoclinic	Biaxial	(-)	0.046	None
Garnet	Cubic crystal system	none (isotropic)	N/A	N/A	None
Glauconite	Monoclinic	Biaxial	(-)	0.032	Light Blue
Glaucophane	Monoclinic	Biaxial	(-)	0.021	Blue Pleochroic
Microcline	Triclinic	Biaxial	(-)	0.010	None
Muscovite	Monoclinic	Biaxial	(-)	0.042	None
Olivine	Orthorombic	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

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References

1. https://www.mindat.org