Dispersion in Gemology
| Name | B–G | C–F |
|---|---|---|
| Cinnabar (HgS) | 0.40 | – |
| Synth. rutile | 0.330 | 0.190 |
| Rutile (TiO2) | 0.280 | 0.120–0.180 |
| Anatase (TiO2) | 0.213–0.259 | – |
| Wulfenite | 0.203 | 0.133 |
| Vanadinite | 0.202 | – |
| Fabulite | 0.190 | 0.109 |
| Sphalerite (ZnS) | 0.156 | 0.088 |
| Sulfur (S) | 0.155 | – |
| Stibiotantalite | 0.146 | – |
| Goethite (FeO(OH)) | 0.14 | – |
| Brookite (TiO2) | 0.131 | 0.12–1.80 |
| Zincite (ZnO) | 0.127 | – |
| Linobate | 0.13 | 0.075 |
| Synth. moissanite (SiC) | 0.104 | – |
| Cassiterite (SnO2) | 0.071 | 0.035 |
| Zirconia (ZrO2) | 0.060 | 0.035 |
| Powellite (CaMoO4) | 0.058 | – |
| Andradite | 0.057 | – |
| Demantoid | 0.057 | 0.034 |
| Cerussite | 0.055 | 0.033–0.050 |
| Titanite | 0.051 | 0.019–0.038 |
| Benitoite | 0.046 | 0.026 |
| Anglesite | 0.044 | 0.025 |
| Diamond (C) | 0.044 | 0.025 |
| Flint glass | 0.041 | – |
| Hyacinth | 0.039 | – |
| Jargoon | 0.039 | – |
| Starlite | 0.039 | – |
| Zircon (ZrSiO4) | 0.039 | 0.022 |
| GGG | 0.038 | 0.022 |
| Scheelite | 0.038 | 0.026 |
| Dioptase | 0.036 | 0.021 |
| Whewellite | 0.034 | – |
| Alabaster | 0.033 | – |
| Gypsum | 0.033 | 0.008 |
| Epidote | 0.03 | 0.012–0.027 |
| Achroite | 0.017 | – |
| Cordierite | 0.017 | 0.009 |
| Danburite | 0.017 | 0.009 |
| Dravite | 0.017 | – |
| Elbaite | 0.017 | – |
| Herderite | 0.017 | 0.008–0.009 |
| Hiddenite | 0.017 | 0.010 |
| Indicolite | 0.017 | – |
| Liddicoatite | 0.017 | – |
| Kunzite | 0.017 | 0.010 |
| Rubellite | 0.017 | 0.008–0.009 |
| Schorl | 0.017 | – |
| Scapolite | 0.017 | – |
| Spodumene | 0.017 | 0.010 |
| Tourmaline | 0.017 | 0.009–0.011 |
| Verdelite | 0.017 | – |
| Andalusite | 0.016 | 0.009 |
| Baryte (BaSO4) | 0.016 | 0.009 |
| Euclase | 0.016 | 0.009 |
| Alexandrite | 0.015 | 0.011 |
| Chrysoberyl | 0.015 | 0.011 |
| Hambergite | 0.015 | 0.009–0.010 |
| Phenakite | 0.01 | 0.009 |
| Rhodochrosite | 0.015 | 0.010–0.020 |
| Sillimanite | 0.015 | 0.009–0.012 |
| Smithsonite | 0.014–0.031 | 0.008–0.017 |
| Amblygonite | 0.014–0.015 | 0.008 |
| Aquamarine | 0.014 | 0.009–0.013 |
| Beryl | 0.014 | 0.009–0.013 |
| Brazilianite | 0.014 | 0.008 |
| Celestine | 0.014 | 0.008 |
| Goshenite | 0.014 | – |
| Heliodor | 0.014 | 0.009–0.013 |
| Morganite | 0.014 | 0.009–0.013 |
| Pyroxmangite | 0.015 | – |
| Synth. scheelite | 0.015 | – |
| Dolomite | 0.013 | – |
| Magnesite (MgCO3) | 0.012 | – |
| Synth. emerald | 0.012 | – |
| Synth. alexandrite | 0.011 | – |
| Synth. sapphire (Al2O3) | 0.011 | – |
| Phosphophyllite | 0.010–0.011 | – |
| Enstatite | 0.010 | – |
| Anorthite | 0.009–0.010 | – |
| Actinolite | 0.009 | – |
| Jeremejevite | 0.009 | – |
| Nepheline | 0.008–0.009 | – |
| Apophyllite | 0.008 | – |
| Hauyne | 0.008 | – |
| Natrolite | 0.008 | – |
| Synth. quartz (SiO2) | 0.008 | – |
| Aragonite | 0.007–0.012 | – |
| Augelite | 0.007 | – |
| Tanzanite | 0.030 | 0.011 |
| Thulite | 0.03 | 0.011 |
| Zoisite | 0.03 | – |
| YAG | 0.028 | 0.015 |
| Almandine | 0.027 | 0.013–0.016 |
| Hessonite | 0.027 | 0.013–0.015 |
| Spessartine | 0.027 | 0.015 |
| Uvarovite | 0.027 | 0.014–0.021 |
| Willemite | 0.027 | – |
| Pleonaste | 0.026 | – |
| Rhodolite | 0.026 | – |
| Boracite | 0.024 | 0.012 |
| Cryolite | 0.024 | – |
| Staurolite | 0.023 | 0.012–0.013 |
| Pyrope | 0.022 | 0.013–0.016 |
| Diaspore | 0.02 | – |
| Grossular | 0.020 | 0.012 |
| Hemimorphite | 0.020 | 0.013 |
| Kyanite | 0.020 | 0.011 |
| Peridote | 0.020 | 0.012–0.013 |
| Spinel | 0.020 | 0.011 |
| Vesuvianite | 0.019–0.025 | 0.014 |
| Clinozoisite | 0.019 | 0.011–0.014 |
| Labradorite | 0.019 | 0.010 |
| Axinite | 0.018–0.020 | 0.011 |
| Ekanite | 0.018 | 0.012 |
| Kornerupine | 0.018 | 0.010 |
| Corundum (Al2O3) | 0.018 | 0.011 |
| Rhodizite | 0.018 | – |
| Ruby (Al2O3) | 0.018 | 0.011 |
| Sapphire (Al2O3) | 0.018 | 0.011 |
| Sinhalite | 0.018 | 0.010 |
| Sodalite | 0.018 | 0.009 |
| Synth. corundum | 0.018 | 0.011 |
| Diopside | 0.018–0.020 | 0.01 |
| Emerald | 0.014 | 0.009–0.013 |
| Topaz | 0.014 | 0.008 |
| Amethyst (SiO2) | 0.013 | 0.008 |
| Anhydrite | 0.013 | – |
| Apatite | 0.013 | 0.010 |
| Apatite | 0.013 | 0.008 |
| Aventurine | 0.013 | 0.008 |
| Citrine | 0.013 | 0.008 |
| Morion | 0.013 | – |
| Prasiolite | 0.013 | 0.008 |
| Quartz (SiO2) | 0.013 | 0.008 |
| Smoky quartz (SiO2) | 0.013 | 0.008 |
| Rose quartz (SiO2) | 0.013 | 0.008 |
| Albite | 0.012 | – |
| Bytownite | 0.012 | – |
| Feldspar | 0.012 | 0.008 |
| Moonstone | 0.012 | 0.008 |
| Orthoclase | 0.012 | 0.008 |
| Pollucite | 0.012 | 0.007 |
| Sanidine | 0.012 | – |
| Sunstone | 0.012 | – |
| Beryllonite | 0.010 | 0.007 |
| Cancrinite | 0.010 | 0.008–0.009 |
| Leucite | 0.010 | 0.008 |
| Obsidian | 0.010 | – |
| Strontianite | 0.008–0.028 | – |
| Calcite (CaCO3) | 0.008–0.017 | 0.013–0.014 |
| Fluorite (CaF2) | 0.007 | 0.004 |
| Hematite | 0.500 | – |
| Synth. cassiterite (SnO2) | 0.041 | – |
| Gahnite | 0.019–0.021 | – |
| Datolite | 0.016 | – |
| Tremolite | 0.006–0.007 | – |
In the technical terminology of gemology, dispersion is the difference in the refractive index of a material at the B and G (686.7 nm and 430.8 nm) or C and F (653.3 nm and 486.1 nm) Fraunhofer wavelengths, and is meant to express the degree to which a prism cut from the gemstone shows "fire", or color. Dispersion is a material property. Fire depends on the dispersion, the cut angles, the lighting environment, the refractive index, and the viewer.
Read more about this topic: Dispersion (optics)
Famous quotes containing the word dispersion:
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