Table of Refractive Index and Double Refraction of Gems


GemstoneRefractive IndexDouble Refraction
Hematite2.940 – 3.2200.287
Cinnabar2.905 – 3.2560.351
Proustite2.881 – 3.0840.203
Pyrargyrite2.88 – 3.080.200
Cuprite2.849none
Rutile2.616 – 2.9030.287
Brookite2.583 – 2.7000.117
Anatase2.488 – 2.5640.046 – 0.067
Diamond2.417 – 2.419anomalous
Fabulite2.409none
Stibiotantalite2.370 – 2.4500.080
Sphalerite2.368 – 2.371none
Crocoite2.29 – 2.660.270
Wulfenite2.280 – 2.4000.120
Tantalite2.26 – 2.430.160
Linobate2.21 – 2.300.090
Manganotantalite2.19 – 2.340.150
Cubic Zirconia2.150 – 2.180none
Mimetite2.120 – 2.1350.015
Phosgenite2.114 – 2.1450.028
Senarmontite2.087none
Boleite2.03 – 2.050.020
Zincite2.013 – 2.0290.016
Cassiterite1.997 – 2.0980.096 – 0.098
Simpsonite1.994 – 2.0400.058
GGG1.970 – 2.0200.058
Sulphur1.958 – 2.2450.291
Bayldonite1.95 – 1.990.04
Scheelite1.918 – 1.9370.010 – 0.018
Andradite1.88 – 1.94none
Anglesite1.878 – 1.8950.017
Uvarovite1.865none
Purpurite1.85 – 1.920.007
Titanite1.843 – 2.1100.100 – 0.192
YAG1.833 – 1.835none
Zircon1.810 – 2.0240.0002 – 0.059
Cerussite1.804 – 2.0790.274
Gahnite1.791 – 1.818none
Spessartine1.790 – 1.820none
Painite1.787 – 1.8160.029
Monazite1.774 – 1.8490.049 – 0.055
Almandine1.770 – 1.820none
Gadolinite1.77 – 1.820.01 – 0.04
Ruby1.762 -1.7780.008
Sapphire1.762 -1.7780.008
Benitoite1.757 – 1.8040.047
Shattuckite1.752 – 1.8150.063
Chrysoberyl1.746 – 1.7630.007 – 0.011
Periclase1.74none
Scorodite1.738 – 1.8160.027 – 0.030
Staurolite1.736 – 1.7620.010 – 0.015
Grossular1.734 – 1.759none
Chambersite1.732 – 1.7440.012
Hessonite1.730 – 1.757none
Epidote1.729 – 1.7680.015 – 0.049
Pyroxmangite1.726 – 1.7640.016 – 0.020
Azurite1.720 – 1.8480.108 – 0.110
Pyrope1.720 – 1.756none
Hodgkinsonite1.719 – 1.7480.022 – 0.026
Taaffeite1.719 – 1.7300.004 – 0.009
Rhodonite1.716 – 1.7520.010 – 0.014
Gahnospinel1.715 – 1.754none
Spinel1.712 – 1.762none
Kyanite1.710 – 1.7340.015 – 0.033
Adamite1.708 – 1.7600.048 – 0.050
Diaspore1.702 – 1.7500.048
Serendibite1.701 – 1.7430.005
Sapphirine1.701 – 1.7340.004 – 0.007
Aegirine-augite1.700 – 1.8000.030 – 0.050
Vesuvianite1.700 – 1.7230.002 – 0.012
Tanzanite1.691 – 1.7000.009
Neptunite1.690 – 1.7360.029 – 0.045
Willemite1.690 – 1.7230.028 – 0.033
Rhodizite1.690none
Triphylite1.689 – 1.7020.006 – 0.008
Lithiophilite1.68 – 1.700.01
Dumortierite1.678 – 1.6890.015 – 0.037
Legrandite1.675 – 1.7400.060
Hypersthene1.673 – 1.7310.010 – 0.016
Parisite1.671 – 1.7720.081 – 0.101
Clinozoisite1.670 – 1.7340.010
Sinhalite1.665 – 1.7120.036 – 0.042
Lawsonite1.665 – 1.6860.019 – 0.021
Diopside1.664 – 1.7300.024 – 0.031
Bustamite1.662 – 1.7070.014 – 0.015
Cornerupine1.660 – 1.6990.012 – 0.017
Hiddenite1.660 – 1.6810.014 – 0.016
Kunzite1.660 – 1.6810.014 – 0.016
Boracite1.658 – 1.6730.010 – 0.011
Axinite1.656 – 1.7040.010 – 0.012
Malachite1.655 – 1.9090.254
Sillimanite1.655 – 1.6840.014 – 0.021
Jadeite1.652 – 1.6880.20
Peridot1.650 – 1.7030.036 – 0.038
Ludlamite1.650 – 1.6970.038 – 0.044
Enstatite1.650 – 1.6800.009 – 0.012
Euclase1.650 – 1.6770.019 – 0.025
Phenakite1.650 – 1.6700.016
Dioptase1.644 – 1.7090.051 – 0.053
Jet1.640 – 1.680none
Eosphorite1.638 – 1.6710.028 – 0.035
Spurrite1.637 – 1.6810.039 – 0.040
Jeremejevite1.637 0 1.6530.007 – 0.013
Baryte1.636 – 1.6480.012
Siderite1.633 – 1.8750.242
Danburite1.630 – 1.6360.006 – 0.008
Clinohumite1.629 – 1.6740.028 – 0.041
Apatite1.628 – 1.6490.002 – 0.006
Andalusite1.627 – 1.6490.007 – 0.013
Friedelite1.625 -1.6640.030
Smithsonite1.621 – 1.8490.228
Datolite1.621 – 1.6750.040 – 0.050
Celestine1.619 – 1.6350.010 – 0.012
Tourmaline1.614 – 1.6660.014 – 0.032
Actinolite1.614 – 1.6530.020 – 0.025
Hemimorphite1.614 – 1.6360.022
Lazulite1.612 – 1.6460.031 – 0.036
Prehnite1.611 – 1.6690.021 – 0.039
Gaspéite1.61 – 1.810.22
Turquoise1.610 – 1.6500.040
Topaz1.609 – 1.6430.008 – 0.016
Sugilite1.607 – 1.6110.001 – 0.004
Sogdianite1.606 – 1.6080.002
Brazilianite1.602 – 1.6230.019 – 0.021
Rhodochrosite1.600 – 1.8200.208 – 0.220
Odontolite1.60 – 1.640.010
Nephrite1.600 – 1.6270.027
Pectolite1.595 – 1.6450.038
Montebrasite1.594 -1.6330.22
Phosphophyllite1.594 – 1.6210.021 – 0.033
Meliphanite1.593 – 1.6120.019
Eudialyte1.591 -1.6330.003 – 0.010
Chondrodite1.592 – 1.6460.028 – 0.034
Catapleiite1.590 – 1.6290.039
Wardite1.590 – 1.5990.009
Herderite1.587 – 1.6270.023 – 0.032
Colemanite1.586 – 1.6150.028 – 0.030
Howlite1.586 – 1.6050.019
Zektzerite1.582 – 1.5850.003
Amblygonite1.578 – 1.6460.024 – 0.030
Ekanite1.572 – 1.5730.001
Anhydrite1.570 – 1.6140.044
Augelite1.570 – 1.5900.014 – 0.020
Emerald1.565 – 1.6020.006
Aquamarine1.564 – 1.5960.004 – 0.005
Variscite1.563 – 1.5940.031
Precious Beryl1.562 – 1.6020.004 – 0.010
Tremolite1.560 – 1.6430.017 – 0.027
Vivianite1.560 – 1.6400.050 – 0.075
Serpentine1.560 – 1.5710.008 – 0.014
Larbradorite1.559 – 1.5700.008 – 0.010
Hambergite1.553 – 1.6280.072
Pyrophyllite1.552 – 1.6000.048
Muscovite1.552 – 1.6180.036 – 0.043
Beryllonite1.552 – 1.5610.009
Charoite1.550 – 1.5610.004 – 0.009
Amethyst1.544 – 1.5530.009
Aventurine1.544 – 1.5530.009
Rock Crystal1.544 – 1.5530.009
Citrine1.544 – 1.5530.009
Prasiolite1.544 – 1.5530.009
Smoky quartz1.544 – 1.5530.009
Rose quartz1.544 – 1.5530.009
Andesine1.543 – 1.5510.008
Cordierite1.542 – 1.5780.008 – 0.012
Oligoclase1.542 – 1.5490.007
Talc1.54 – 1.590.050
Scapolite1.540 – 1.5790.006 – 0.037
Amethyst1.54 – 1.550009 Quartz
Petrified Wood1.54none
Jasper1.54none
Amber1.539 – 1.545none
Ivory1.535 – 1.570none
Apophyllite1.535 – 1.5370.002
Tiger’s-eye1.534 – 1.540none
Aragonite1.530 – 1.6850.155
Agate1.530 -1.5400.004 – 0.009
Chalcedony1.530 -1.5400.004 – 0.009
Chrysoprase1.530 -1.5400.004 – 0.009
Moss agate1.530 -1.5400.004 – 0.009
Sepiolite1.53none
Witherite1.529 – 1.6770.148
Milarite1.529 -1.5510.003
Nepheline1.526 – 1.5460.0004
Sunstone1.525 – 1.5480.01
Amazonite1.522 – 1.5300.008
Pearl1.52 – 1.690.156
Ammonite1.52 – 1.680.155
Strontianite1.52 – 1.670.150
Gypsum1.520 – 1.5290.009
Orthoclase1.518 – 1.5300.008
Sanidine1.518 – 1.5300.008
Moonstone1.518 – 1.5260.008
Pollucite1.517 – 1.525none
Carletonite1.517 – 1.5210.004
Stichtite1.516 – 1.5440.026
Thomsonite1.515 – 1.5420.006 – 0.025
Magnesite1.509 – 1.7170.022
Scolecite1.509 – 1.5250.007 – 0.012
Leucite1.504 – 1.5090.001
Mesolite1.504 – 1.5080.001
Dolomite1.502 – 1.6980.185
Petalite1.502 – 1.5190.012 – 0.017
Lapis Lazuli1.5none
Haüyne1.496 – 1.510none
Tugtupite1.496 – 1.5020.006
Cancrinite1.495 – 1.5280.024 – 0.029
Celluloid1.495 – 1.520none
Ulexite1.491 – 1.5200.029
Yugawaralite1.490 – 1.5090.011 – 0.014
Whewellite1.489 – 1.6510.159 – 0.163
Kurnakovite1.488 – 1.5250.036
Inderite1.486 – 1.5070.017 – 0.020
Calcite1.486 – 1.6580.172
Coral1.486 – 1.6580.160 -0.172
Moldavite1.48 – 1.54none
Natrolite1.480 – 1.4930.013
Sodalite1.48none
Analcime1.479 – 1.489none
Thaumasite1.464 – 1.5070.036
Creedite1.461 – 1.4850.024
Chrysocolla1.460 – 1.5700.023 – 0.040
Obsidian1.45 – 1.55none
Gaylussite1.443 – 1.5230.080
Glass1.44 – 1.90none
Fluorite1.434none
Sellaite1.378 -1.3900.012
Opal1.37 – 1.52none