Mineral Refractive Index Birefringence
no guarantee from various sources from various sources
     
Quartz 1.543 - 1.554 0.009
Red Beryl 1.561 - 1.598  0.004 - 0.007
Remondite-(Ce) 1.632 - 1.638 0.006
Rhodizite 1.690 0.000
Rhodochrosite 1.578 - 1.840 0.218 - 0.220
Rhodolite 1.745 - 1.760  0.000
Rhodonite 1.711 - 1.752 0.011 - 0.014
Richterite 1.615 - 1.636 0.021
Ruby 1.757 - 1.779  0.008
Rutile 2.616 - 2.903  0.259 - 0.294
Sanidine 1.522 - 1.537 0.005 - 0.008
Sapphire 1.757 - 1.779   0.008
Sapphirine 1.714 - 1.723 0.006 - 0.007
Scapolite 1.540 - 1.579 0.004 - 0.038
Scheelite 1.918 - 1.936 0.016 - 0.017
Scolecite 1.509 - 1.525 0.008 - 0.010
Scorodite 1.738 - 1.816 0.027 - 0.036
Sellaite 1.378 - 1.390 0.012
Serandite 1.674 - 1.71 0.035 - 0.036
Serendibite 1.701 - 1.706 0.005
Shomiokite-(Y) 1.528 - 1.531 0.003
Shortite 1.531 - 1.570 0.039
Siderite 1.633 - 1.875 0.240 - 0.242
Sillimanite 1.653 - 1,684 0.016 - 0.023
Simpsonite 1.976 - 2.045 0.020
Sinhalite 1.665 - 1.712 0.036 - 0.039
Smithsonite 1.610 - 1.850 0.225
Sodalite 1.480 - 1.483 0.000
Spessartine 1.790 - 1.820 0.000
Sphalerite 2.368 - 2.371 0.000
Spherocobaltite 1.885 - 1.600 0.285
Spinel 1.708 - 1.735   0.000
Spodumene 1.653 - 1.682 0.014 - 0.016
Staurolite 1.736 - 1.762 0.009 - 0.015
Stibiotantalite 2.374 - 2.457 0.083
Stolzite 2.18 - 2.27 0.080 - 0.090
Sugilite 1.607 - 1.611 0.003 - 0.004
Sussexite 1.67 - 1.73 0.062
Taaffeite 1.717 - 1.730 0.00475
Tanzanite 1.690 - 1.705 0.008 - 0.013
Thaumasite 1.464 - 1.507 0.039
Tiger's eye 1.534 - 1.540 0.009
Titanite / Sphene 1.885 - 2.034 0.100 - 0.192
Topaz 1.606 - 1.643 0.008 - 0.010
Topazolite 1.850 - 1.899 0.000
Tourmaline 1.603 - 1.666 0.006 - 0.080
Tremolite 1.599 - 1.637 0.017 - 0.028
Triphylite 1.689 - 1.702 0.006 - 0.008
Triplite 1.65 - 1.68 0.030
Tsavorite 1.735 - 1.744  0.000
Tugtupite 1.496 - 1.502 0.006
Turquoise 1.610 - 1.650 0.040
Ussingite 1.504 - 1.545 0.039 - 0.041
Uvarovite 1.860 - 1.870 0.000
Vaeyrynenite 1.638 - 1.667 0.026 - 0.027
Viridine 1.634 - 1.643 0.003 - 0.007
Vlasovite 1.607 - 1.628 0.019 - 0.021
Wavellite 1.518 - 1.561 0.025 - 0.026
Whewellite 1.489 - 1.651 0.16
Willemite 1.690 - 1.724 0.028
Witherite 1.529 - 1.677 0.148
Wulfenite 2.280 - 2.405 0.122
Xenotime-(Y) 1.720 - 1.827 0.095
Xonotlite 1.583 - 1.595 0.012
Yugawaralite 1.490 - 1.509 0.009
Zektzerite 1.582 - 1.584 0.002
Zircon 1.777 - 2.025  0.047 - 0.055
Zoisite 1.685 - 1.725 0.006 - 0.018