| 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 |