Birefringence : ClassicGems.net

Birefringence

Birefringence is the difference between the high and low Refractive Index (RI) values of a gemstone. Careful rotation of the gemstone and repeated readings on a refractometer will usually provide the maximum spread between the refractive indices which is equal to the Birefringence of the gemstone. Birefringence values are often useful in quickly narrowing possible choices during gemstone indentification work. The first list below is in alphabetical order. The second list is in numerical order of birefrigence from highest to lowest. Click here to view the numerical list.


	Gems (in alphabetical order)	birefrigence
	Actinolite Adventurine (Quartz) Agate Air (as a reference) Albite (Feldspar) Alexandrite Allanite Almandine (Garnet) Amazonite (Feldspar) Amber Amblygonite Amethyst Ametrine Anatase Andalusite Andesine (Feldspar) Andradite (Garnet) Angelsite Anhydrite Anorthite (Feldspar) Apatite Apophyllite Aquamarine (Beryl) Aragonite Augelite Axinite Azurite Barite Benitoite Beryl Family Beryllonite Bixbite (Beryl) Boleite Boracite Brazilianite Bronzite Brookite Brucite Bustamite Bytownite (Feldspar) Calcite Cancrinite Carnelian Cassiterite Catapleiite Celestite Cerussite Chalcedony Chambersite Charoite Childrenite Chrome Diopside Chrysoberyl Chrysocolla Chrysoprase Citrine Clinohumite Clinozoisite Colemanite Coral Creedite Crocoite Cubic Zirconia Cuprite Danburite Datolite Demantoid (Garnet) Diamond Diaspore Diopside Dioptase Dolomite Dumortierite Ekanite Emerald (Beryl) Emerald (synth. flux) Emerald (synth. hydro) Enstatite Eosphorite Epidote Euclase Eudialyte Fayalite (Olivine) Fluorite Friedelite Gahnite Gahnospinel Glass (man-made) Goshenite (Beryl) Grossular (Garnet) Hackmanite Hambergite Hauyne Heliodor (Beryl) Hematite Hemimorphite Herderite Hessonite (Garnet) Hiddenite (Spodumene) Howlite Hydrogrossular (Garnet) Hypersthene Idocrase Iolite Jadeite (Jade) Jasper (Quartz) Jeremejevite Kornerupine Kunzite (Spodumene) Kyanite Labradorite (Feldspar) Lapis Lazuli (Lazurite) Lazulite Legrandite Leucite Magnesite Malachite Manganotantalite Microline (Feldspar) Microlite Moissanite Moldavite Monazite Montebrasite Moonstone (Feldspar) Morganite (Beryl) Nambulite Natrolite Nepheline Nephrite (Jade) Neptunite Obsidian Oligoclase (Feldspar) Onyx Opal Orthoclase (Feldspar) Painite Parisite Pearl Pectolite Periclase Peridot (Olivine) Peristerite (Feldspar) Petalite Phenakite Phosgenite Phosphophyllite Poudretteite Powellite Prasiolite (Quartz) Prehnite Proustite Purpurite Pyrope (Garnet) Pyroxmangite Quartz (all colors) Rhodizite Rhodochrosite Rhodolite (Garnet) Rhodonite Ruby (Corundum) Rutile Sanidine (Feldspar) Sapphire (Corundum) Sapphirine Scapolite Scheelite Sellaite Serandite Serpentine Shattuckite Shortite Siderite Sillimanite Simpsonite Sinhalite Smithsonite Sodalite Spessartite (Garnet) Sphalerite Sphene Spinel Spinel (synthetic) Spodumene Staurolite Strontium Titanate Sugilite Sunstone (Feldspar) Taaffeite Tantalite Tanzanite (Zoisite) Tektite Thaumasite Thomsonite Thulite (Zoisite) Tiger eye (Quartz) Topaz Tourmaline (all colors) Tremolite Triphylite Tsavorite (Garnet) Tugtupite Turquoise Ulexite Uvarovite (Garnet) Vanadinite Variscite Vesuvianite Villiamumite Vivianite Water Weloganite Whewellite Willemite Witherite Wulfenite Yugawaralite Zektzerite Zincite Zircon, High Zircon, Medium Zircon, Low Zoisite	0.022 - 0.026 0.009 0.004 0.000 0.011 0.009 - 0.010 0.013 - 0.036 0.000 (iso) 0.008 - 0.010 0.000 0.020 - 0.021 0.009 0.009 0.046 - 0.067 0.007 - 0.011 0.008 0.000 (iso) 0.017 0.044 0.013 0.001 - 0.013 0.001 or less 0.005 - 0.007 0.155 0.014 - 0.020 0.010 - 0.012 0.110 0.012 0.047 0.004 - 0.009 0.009 0.004 - 0.008 0.020 0.024 0.019 - 0.021 0.015 0.122 - 0.157 0.010 - 0.020 0.014 - 0.015 0.009 0.172 - 0.190 0.022 0.004 0.098 0.280 0.009 - 0.012 0.274 0.004 0.012 0.009 0.030 - 0.040 0.028 0.008 - 0.012 0.023 - 0.040 0.004 0.009 0.028 - 0.041 0.005 - 0.015 0.028 0.160 0.024 0.270 0.000 (iso) 0.000 (iso) 0.006 - 0.008 0.044 - 0.047 0.000 (iso) 0.000 (iso) 0.048 0.024 - 0.031 0.053 0.179 - 0.185 0.150 - 0.370 0.001 0.004 - 0.009 0.003 - 0.005 0.003 - 0.008 0.010 0.029 - 0.035 0.015 - 0.049 0.019 - 0.025 0.003 - 0.010 0.052 0.000 (iso) 0.030 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.004 - 0.008 0.000 (iso) 0.000 (iso) 0.072 0.000 (iso) 0.005 - 0.009 0.280 0.022 0.029 - 0.030 0.000 (iso) 0.014 - 0.027 0.022 0.000 (iso) 0.017 0.003 - 0.018 0.005 - 0.018 0.012 - 0.020 0.000 0.007 - 0.013 0.013 - 0.017 0.014 - 0.027 0.017 0.012 0.000 (iso) 0.031 - 0.036 0.060 0.000 (iso) 0.022 0.254 0.150 0.008 - 0.010 0.000 0.043 0.000 (iso) 0.049 - 0.055 0.021 - 0.022 0.005 - 0.008 0.008 - 0.009 0.023 0.012 0.004 0.027 0.029 - 0.045 0.000 (iso) 0.007 0.004 0.000 (iso) 0.005 - 0.008 0.027 - 0.028 0.081 0.155 0.036 0.000 (iso) 0.033 - 0.038 0.011 0.012 - 0.014 0.016 0.028 0.021 - 0.033 0.016 - 0.021 0.011 0.009 0.021 - 0.033 0.296 0.007 0.000 (iso) 0.016 - 0.020 0.009 0.000 (iso) 0.201 - 0.220 0.000 (iso) 0.011 - 0.014 0.008 - 0.009 0.287 0.005 - 0.008 0.008 - 0.009 0.006 0.015 - 0.026 0.016 0.012 0.028 0.014 0.063 0.039 0.240 0.020 0.058 0.035 - 0.037 0.227 0.000 (iso)1 0.000 (iso) 0.000 (iso) 0.100 - 0.192 0.000 (iso) 0.000 (iso) 0.014 - 0.027 0.011 - 0.015 0.000 (iso) 0.003 - 0.005 0.012 0.004 - 0.009 0.160 0.009 0.000 (iso) 0.036 0.021 0.006 0.009 0.008 - 0.011 0.020 0.017 - 0.027 0.006 - 0.008 0.000 (iso) 0.006 - 0.008 0.040 0.023 0.000 (iso) 0.066 0.031 0.003 - 0.018 0.000 (iso) 0.040 - 0.059 0.000 0.090 0.159 - 0.163 0.028 0.148 0.122 0.009 0.002 0.016 0.000 - 0.008 0.008 - 0.043 0.036 - 0.059 0.004 - 0.008
	Numerical Birefingence List
	0.296 0.287 0.280 0.280 0.274 0.270 0.254 0.240 0.227 0.201 - 0.220 0.179 - 0.185 0.172 - 0.190 0.160 0.160 0.159 - 0.163 0.155 0.155 0.150 - 0.370 0.150 0.148 0.122 - 0.157 0.122 0.110 0.100 - 0.192 0.098 0.090 0.081 0.072 0.066 0.063 0.060 0.058 0.053 0.052 0.049 - 0.055 0.048 0.047 0.046 - 0.067 0.044 - 0.047 0.044 0.043 0.040 - 0.059 0.040 0.039 0.036 - 0.059 0.036 0.036 0.035 - 0.037 0.033 - 0.038 0.031 - 0.036 0.031 0.030 - 0.040 0.030 0.029 - 0.045 0.029 - 0.035 0.029 - 0.030 0.029 0.028 - 0.041 0.028 0.028 0.028 0.028 0.028 0.027 - 0.028 0.027 0.024 - 0.031 0.024 0.024 0.023 - 0.040 0.023 0.023 0.022 - 0.026 0.022 0.022 0.022 0.022 0.021 - 0.033 0.021 - 0.033 0.021 - 0.022 0.021 0.020 - 0.021 0.020 0.020 0.020 0.019 - 0.025 0.019 - 0.021 0.017 - 0.027 0.017 0.017 0.017 0.016 - 0.021 0.016 - 0.020 0.016 0.016 0.016 0.015 - 0.049 0.015 - 0.026 0.015 0.014 - 0.027 0.014 - 0.027 0.014 - 0.027 0.014 - 0.020 0.014 - 0.015 0.014 0.013 - 0.036 0.013 - 0.017 0.013 0.012 - 0.020 0.012 - 0.014 0.012 0.012 0.012 0.012 0.012 0.012 0.011 - 0.015 0.011 - 0.014 0.011 0.011 0.011 0.010 - 0.020 0.010 - 0.012 0.010 0.009 - 0.012 0.009 - 0.010 0.009 0.009 0.009 0.009 0.009 0.009 0.009 0.009 0.009 0.009 0.009 0.009 0.008 - 0.043 0.008 - 0.012 0.008 - 0.011 0.008 - 0.010 0.008 - 0.010 0.008 - 0.009 0.008 - 0.009 0.008 - 0.009 0.008 0.007 - 0.013 0.007 - 0.011 0.007 0.007 0.006 - 0.008 0.006 - 0.008 0.006 - 0.008 0.006 0.006 0.005 - 0.018 0.005 - 0.015 0.005 - 0.009 0.005 - 0.008 0.005 - 0.008 0.005 - 0.008 0.005 - 0.007 0.004 - 0.009 0.004 - 0.009 0.004 - 0.009 0.004 - 0.008 0.004 - 0.008 0.004 - 0.008 0.004 0.004 0.004 0.004 0.004 0.004 0.003 - 0.018 0.003 - 0.018 0.003 - 0.010 0.003 - 0.008 0.003 - 0.005 0.003 - 0.005 0.002 0.001 - 0.013 0.001 0.001 or less 0.000 - 0.008 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 (iso) 0.000 0.000 0.000 0.000 0.000	Proustite Rutile Catapleiite Hematite Cerussite Crocoite Malachite Siderite Smithsonite Rhodochrosite Dolomite Calcite Coral Tantalite Whewellite Aragonite Pearl Dumortierite Manganotantalite Witherite Brookite Wulfenite Azurite Sphene Cassiterite Weloganite Parisite Hambergite Vanadinite Shattuckite Legrandite Simpsonite Dioptase Fayalite (Olivine) Monazite Diaspore Benitoite Anatase Datolite Anhydrite Moissanite Vivianite Turquoise Shortite Zircon, Low Pectolite Thaumasite Sinhalite Peridot (Olivine) Lazulite Variscite Childrenite Friedelite Neptunite Eosphorite Herderite Painite Clinohumite Chrome Diopside Colemanite Phosgenite Serandite Willemite Painite Nephrite (Jade) Diopside Boracite Creedite Chrysocolla Nambulite Ulexite Actinolite Cancrinite Hemimorphite Howlite Magnesite Phosphophyllite Prehnite Montebrasite Thomsonite Amblygonite Boleite Sillimanite Tourmaline (all colors) Euclase Brazilianite Tremolite Angelsite Hypersthene Kyanite Poudretteite Pyroxmangite Phenakite Scheelite Zincite Epidote Scapolite Bronzite Hiddenite (Spodumene) Kunzite (Spodumene) Spodumene Augelite Bustamite Serpentine Allanite Kornerupine Anorthite (Feldspar) Jadeite (Jade) Petalite Barite Chambersite Labradorite (Feldspar) Natrolite Sellaite Sunstone (Feldspar) Staurolite Rhodonite Albite (Feldspar) Peristerite (Feldspar) Powellite Brucite Axinite Enstatite Celestite Alexandrite Adventurine (Quartz) Amethyst Ametrine Beryllonite Bytownite (Feldspar) Charoite Citrine Prasiolite (Quartz) Quartz (all colors) Tanzanite (Zoisite) Tiger eye (Quartz) Yugawaralite Zircon, Medium Chrysoberyl Topaz Amazonite (Feldspar) Microline (Feldspar) Morganite (Beryl) Ruby (Corundum) Sapphire (Corundum) Andesine (Feldspar) Jeremejevite Andalusite Oligoclase (Feldspar) Purpurite Danburite Triphylite Tugtupite Sapphirine Thulite (Zoisite) Iolite Clinozoisite Heliodor (Beryl) Moonstone (Feldspar) Orthoclase (Feldspar) Sanidine (Feldspar) Aquamarine (Beryl) Beryl Family Emerald (Beryl) Taaffeite Bixbite (Beryl) Goshenite (Beryl) Zoisite Agate Carnelian Chalcedony Chrysoprase Nepheline Onyx Idocrase Vesuvianite Eudialyte Emerald (synth. hydro) Sugilite Emerald (synth. flux) Zektzerite Apatite Ekanite Apophyllite Zircon, High Almandine (Garnet) Andradite (Garnet) Cubic Zirconia Cuprite Demantoid (Garnet) Diamond Fluorite Gahnite Gahnospinel Glass (man-made) Grossular (Garnet) Hackmanite Hauyne Hessonite (Garnet) Hydrogrossular (Garnet) Lapis Lazuli (Lazurite) Leucite Moldavite Obsidian Opal Periclase Pyrope (Garnet) Rhodizite Rhodolite (Garnet) Sodalite Spessartite (Garnet) Sphalerite Spinel Spinel (synthetic) Strontium Titanate Tektite Tsavorite (Garnet) Uvarovite (Garnet) Villiamumite Air (as a reference) Amber Jasper (Quartz) Microlite Water
	Notes: Values may be approximate or may vary by mineral origin and associations with other minerals, or by color or inclusions, and by cleanliness and quality of gemstone polish. (iso) refers to isotropic, meaning that light travels at the same speed in all directions within the gem. These gems have an isometric crystal structure or may be amorphous. Reference: Color Encyclopedia of Gemstones, Second Edition (1987), by Joel E. Arem.