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Read More Gemstone Properties Gemstone Clarity Gemstone Color Gemstone Form Gemstone Crystal System Gemstone Color Chart Luster Cleavage Continue Reading about Gemstone Agate Amber Calcite Diamond Emerald Garnet |
Specific gravities are usually measured with heavy liquids. A liquid is prepared, such as a mixture of bromoform and toluene, to have a specific density value. An unknown material dropped into the liquid may sink, float, or remain suspended in one place within the liquid. If the material sinks, it is denser than the liquid, and if it floats it is less dense. If it remains at one level it has the same density as the liquid. Very accurate measurements of specific gravity can be made by changing the density of a column of liquid through temperature variations and suspending density standards in the column.
An alternative method of measurement is the use of so-called torsion balances, such as the Hanneman balance and the Berman balance used by mineralogists. These devices are designed to weigh a sample first in air and then suspended in a liquid, such as water or toluene. The weights in both media can be measured quite accurately and specific gravities can sometimes be reported to two decimal places.
A major problem in all density measurements is the presence of impurities within the crystal being studied. These impurities hardly ever have the same specific gravity as the host material, and their presence results in measurements that are of limited use for identification purposes. Surface tension may also "float" a mineral grain in both heavy liquids and a torsion balance, resulting in an erroneously low specific gravity measurement. Accurate density measurement involves absolute cleanliness, great care in specimen preparation, accurate temperature control, and replicate measurements.
An alternative method of measurement is the use of so-called torsion balances, such as the Hanneman balance and the Berman balance used by mineralogists. These devices are designed to weigh a sample first in air and then suspended in a liquid, such as water or toluene. The weights in both media can be measured quite accurately and specific gravities can sometimes be reported to two decimal places.
A major problem in all density measurements is the presence of impurities within the crystal being studied. These impurities hardly ever have the same specific gravity as the host material, and their presence results in measurements that are of limited use for identification purposes. Surface tension may also "float" a mineral grain in both heavy liquids and a torsion balance, resulting in an erroneously low specific gravity measurement. Accurate density measurement involves absolute cleanliness, great care in specimen preparation, accurate temperature control, and replicate measurements.
gemstone specific gravity table
Gemstone | Specific Gravity |
---|---|
Agate | 2.60 - 2.65 |
Alexandrite | 3.70 - 3.73 |
Allanite | 3.5 - 4.2 |
Almandine (Garnet) | 4.97 |
Amazonite (Feldspar) | 2.56 - 2.58 |
Amber | 1.08 |
Amblygonite | 3.03 |
Amethyst | 2.63 - 2.65 |
Ametrine | 2.63 - 2.65 |
Anatase | 3.88 |
Andalusite | 3.12 - 3.18 |
Andesine (Feldspar) | 2.68 |
Andradite (Garnet) | 3.859 |
Apatite | 3.21 |
Apophyllite | 2.30 - 2.50 |
Aquamarine (Beryl) | 2.67 - 2.71 |
Aventurine | 2.62 - 2.65 |
Axinite | 3.28 |
Azurite | 3.8 |
Barite | 4.5 |
Bastnäsite | 4.98 |
Benitoite | 3.67 |
Beryl | 2.69 |
Beryllonite | 2.82 |
Bixbite (Beryl) | 2.66 to 2.70 |
Brazilianite | 2.99 |
Bronzite | 3.3 |
Calcite | 3.28 |
Carnelian | 2.82 |
Cassiterite | 4.5 |
Celestite | 3.67 |
Cerussite | 2.69 |
Chalcedony | 2.82 |
Chrome Diopside | 3.22 to 3.38 |
Chrysoberyl | 3.5 to 3.84 |
Chrysocolla | 2.00 to 2.45 |
Chrysoprase | 3.97 to 4.00 |
Citrine | 2.65 |
Clinozoisite | 3.3 to 3.4 |
Colemanite | 2.42 |
Coral | 2.6 to 2.7 |
Crocoite | 5.90 to 6.10 |
Cubic Zirconia | 5.60 - 5.90 |
Cuprite | 5.85 - 6.15 |
Danburite | 3.00 - 3.07 |
Datolite | 2.95 |
Demantoid (Andradite) | 3.82 - 3.85 |
Diamond | 3.52 |
Diopside | 3.29 |
Dioptase | 3.30 |
Dolomite | 2.85 - 2.95 |
Dumortierite | 3.26 - 3.41 |
Ekanite | 3.28 |
Emerald (Beryl) | 2.71 |
Enstatite | 3.27 |
Epidote | 3.45 |
Euclase | 3.10 |
Fayalite (Olivine) | 4.3 |
Fibrolite (sillimanite) | 3.25 |
Fire Opal | 2.00 |
Fluorite | 3.18 |
Gahnite | 3.98 |
Gahnospinel | 3.97 |
Glass (man-made) | 3.15 - 4.20 |
Goshenite (Beryl) | 2.69 |
Grossular (Garnet) | 3.64 |
Hackmanite | 2.15 - 2.40 |
Hambergite | 2.35 |
Hauyne | 2.40 |
Heliodor (Beryl) | 2.69 |
Hematite | 5.05 |
Hemimorphite | 3.45 |
Hessonite (Garnet) | 3.65 |
Hiddenite (Spodumene) | 3.16 - 3.20 |
Howlite | 2.53 - 2.59 |
Hydrogrossular (Garnet) | 3.36 to 3.55 |
Hypersthene | 3.45 |
Idocrase | 3.38 |
Iolite | 2.59 |
Ivory | 1.7 - 2.0 |
Jadeite | 3.34 |
Jasper (Quartz) | 2.58 - 2.91 |
Kornerupine | 3.32 |
Kunzite (Spodumene) | 3.16 - 3.20 |
Kyanite | 3.68 |
Labradorite (Feldspar) | 2.69 |
Lapis Lazuli | 2.80 |
Lazulite | 3.09 |
Leucite | 2.47 |
Magnesite | 3.00 - 3.12 |
Malachite | 3.80 |
Maw-Sit-Sit | 2.50 to 3.50 |
Microline (Feldspar) | 2.56 |
Moissanite | 3.17 to 3.24 |
Moldavite | 2.40 |
Moonstone (Feldspar) | 2.57 |
Morganite (Beryl) | 2.80 to 2.91 |
Natrolite | 2.22 |
Nephrite | 2.90 - 3.04 |
Obsidian | 2.30 - 2.60 |
Oligoclase (Feldspar) | 2.64 to 2.66 |
Onyx | 2.70 |
Opal | 2.10 |
Orthoclase (Feldspar) | 2.6 |
Pearl (cultured) | 2.75 |
Pearl (natural) | 2.71 |
Peridot (Olivine) | 3.34 |
Petalite | 2.39 |
Phenakite | 2.96 |
Prasiolite (Quartz) | 2.65 |
Prehnite | 2.87 |
Proustite | 5.57 - 5.64 |
Purpurite | 3.35 |
Pyrope (Garnet) | 3.70 |
Quartz | 2.65 |
Rhodizite | 3.40 |
Rhodochrosite | 3.60 |
Rhodolite (Garnet) | 3.93 - 4.30 |
Rhodonite | 3.60 |
Ruby (Corundum) | 3.97 - 4.08 |
Rutile | 4.2 |
Sanidine (Feldspar) | 2.57 |
Sapphire (Corundum) | 3.99 - 4.00 |
Sapphirine | 3.54–3.51 |
Scapolite | 2.5 to 2.7 |
Scheelite | 6.00 |
Serpentine | 2.40 - 2.80 |
Sillimanite | 3.25 |
Silver | 10.5 |
Sinhalite | 3.48 |
Smithsonite | 4.35 |
Sodalite | 2.13 - 2.29 |
Spessartine (Garnet) | 4.16 |
Sphalerite | 4.09 |
Sphene | 3.53 |
Spinel | 3.60 |
Spodumene | 3.18 |
Staurolite | 3.70 |
Strontium Titanate | 5.13 |
Taaffeite | 3.61 |
Tantalite | 5.18 - 8.20 |
Tanzanite (Zoisite) | 3.28 - 3.35 |
Thomsonite | 2.35 |
Thulite (Zoisite) | 3.10-3.38 |
Tiger eye (Quartz) | 2.64 - 2.71 |
Topaz (colorless) | 3.56 |
Topaz (yellow) | 3.53 |
Tourmaline | 3.02 - 3.26 |
Tremolite | 2.90 - 3.10 |
Tsavorite (Garnet) | 3.49 |
Tugtupite | 2.37 - 2.57 |
Turquoise | 2.80 |
Ulexite | 1.95 |
Uvarovite (Garnet) | 3.77 |
Vanadinite | 6.6 and 7.2 |
Variscite | 2.55 |
Vesuvianite | 3.35–3.45 |
Vivianite | 2.65 |
Willemite | 4.03 |
Wulfenite | 6.70 - 7.00 |
Zincite | 5.66 |
Zircon, (colorless, blue) | 4.69 |
Zircon, (green) | 4.50 |
Zoisite | 3.10 |
References:
1- Color Encyclopedia of Gemstones, Joel E. Arem, VNR publications, New York.
2- Gemology Project
1- Color Encyclopedia of Gemstones, Joel E. Arem, VNR publications, New York.
2- Gemology Project