Gemstone Density: The Definitive Guide
This illustrated chart shows density or specific gravity ratings for 155 natural gemstone varieties. It is the most complete and accurate density scale for gemstones available online, and includes many rare varieties.
Click on a gem link to see examples or find more information.
| Gem Variety | Density | Chemical Composition |
|
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Cinnabar | 8.0-8.2 | Mercury sulfide |
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Cassiterite | 6.7-7.1 | Tin oxide |
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Cerussite | 6.46-6.57 | Lead carbonate |
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Scheelite | 5.9-6.3 | Calcium tungstate |
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Cuprite | 5.85-6.15 | Copper oxide |
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Hematite | 5.12-5.28 | Iron oxide |
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Barite | 4.43-4.46 | Barium sulfate |
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Spessartite Garnet |
4.12-4.18 | Manganese aluminum silicate |
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Painite | 4.01 | Calcium aluminum zirconium borate |
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Smithsonite | 4.00-4.65 | Zinc carbonate |
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Ruby | 3.97-4.05 | Aluminum oxide |
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Star Ruby | 3.97-4.05 | Aluminum oxide |
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Celestine | 3.97-4.00 | Strontium sulfate |
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Sapphire | 3.95-4.03 | Aluminum oxide |
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Star Sapphire |
3.95-4.03 | Aluminum oxide |
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Zircon | 3.93-4.73 | Zirconium silicate |
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Almandine Garnet |
3.93-4.30 | Iron aluminum silicate |
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Sphalerite | 3.90-4.10 | Zinc sulphide |
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Rhodolite Garnet |
3.84 | Magnesium aluminum silicate |
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Color-Change Garnet |
3.78-3.85 | Complex aluminum silicate |
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Malaia Garnet | 3.78-3.85 | Complex aluminum silicate |
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Gaspeite | 3.71 | Nickel magnesium iron carbonate |
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Demantoid Garnet |
3.7-4.1 | Calcium iron silicate |
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Azurite | 3.77-3.89 | Basic copper carbonate |
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Alexandrite | 3.70-3.78 | Beryllium aluminum oxide |
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Alexandrite Cat's Eye |
3.70-3.78 | Beryllium aluminum oxide |
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Chrysoberyl | 3.70-3.78 | Beryllium aluminum oxide |
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Chrysoberyl Cat's Eye |
3.70-3.78 | Beryllium aluminum oxide |
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Vanadium Chrysoberyl |
3.70-3.78 | Beryllium aluminum oxide |
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Mali Garnet | 3.65 | Calcium aluminum silicate |
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Benitoite | 3.64-3.68 | Barium titanium silicate |
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Pyrope Garnet |
3.62-3.87 | Magnesium aluminum silicate |
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Taaffeite | 3.60-3.62 | Magnesium beryllium aluminum oxide |
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Grossular Garnet |
3.56-3.73 | Calcium aluminum silicate |
 |
Hessonite Garnet |
3.56-3.73 | Calcium aluminum silicate |
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Leuco Garnet | 3.56-3.73 | Calcium aluminum silicate |
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Tsavorite Garnet |
3.56-3.73 | Calcium aluminum silicate |
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Spinel | 3.54-3.63 | Magnesium aluminum oxide |
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Kyanite | 3.53-3.70 | Aluminum silicate |
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Sphene (Titanite) |
3.52-3.54 | Calcium titanium silicate |
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Diamond | 3.50-3.53 | Carbon |
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Imperial Topaz |
3.49-3.57 | Aluminum fluosilicate |
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Topaz | 3.49-3.57 | Aluminum fluosilicate |
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Sinhalite | 3.46-3.50 | Magnesium aluminum borate |
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Rhodochrosite | 3.45-3.70 | Manganese carbonate |
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Serendibite | 3.42-3.52 | Complex borosilicate |
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Uvarovite Garnet |
3.41-3.52 | Calcium chromium silicate |
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Rhodonite | 3.40-3.74 | Manganese silicate |
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Tanzanite | 3.35 | Calcium aluminum silicate |
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Idocrase (Vesuvianite) |
3.32-3.47 | Aluminum calcium silicate |
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Epidote | 3.3-3.5 | Calcium aluminium iron sorosilicate |
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Hemimorphite | 3.30-3.50 | Hydrous basic zinc siilcate |
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Diaspore | 3.30-3.39 | Hydrated aluminum oxide |
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Jadeite Jade | 3.30-3.38 | Sodium aluminum silicate |
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Peridot | 3.28-3.48 | Magnesium iron silicate |
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Dioptase | 3.28-3.38 | Copper cyclosilicate |
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Jeremejevite | 3.28-3.31 | Aluminum borate |
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Kornerupine | 3.27-3.45 | Magnesium aluminum borosilicate |
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Dumortierite | 3.28-3.41 | Aluminum borate silicate |
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Axinite | 3.26-3.36 | Calcium aluminium borosilicate |
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Malachite | 3.25-4.10 | Basic copper carbonate |
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Sillimanite | 3.27-3.27 | Aluminum silicate |
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Chrome Diopside |
3.22-3.38 | Calcium magnesium silicate |
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Diopside | 3.22-3.38 | Calcium magnesium silicate |
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Enstatite | 3.20-3.30 | Magnesium silicate |
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Apatite | 3.16-3.23 | Fluoro or chloro calcium phosphate |
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Cat's Eye Apatite |
3.16-3.23 | Fluoro or chloro calcium phosphate |
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Zoisite | 3.15-3.38 | Calcium aluminum silicate |
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Hiddenite | 3.15-3.21 | Lithium aluminum silicate |
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Kunzite | 3.15-3.21 | Lithium aluminum silicate |
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Spodumene | 3.15-3.21 | Lithium aluminum silicate |
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Clinohumite | 3.13-3.75 | Magnesium silicate |
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Euclase | 3.10 | Beryllium alum. hydroxide silicate |
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Andalusite | 3.05-3.20 | Aluminum silicate |
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Actinolite | 3.03-3.07 | Basic calcium magnesium iron silicate |
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Amblygonite | 3.01-3.11 | Lithium sodium aluminum flurophosphate |
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Fluorite | 3.00-3.28 | Calcium fluoride |
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Brazilianite | 2.98-2.99 | Sodium aluminum phosphate |
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Danburite | 2.97-3.03 | Calcium boric silicate |
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Grandidierite | 2.97-3.03 | Magnesium aluminum borosilicate |
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Phenakite | 2.95-2.97 | Beryllium silicate |
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Aragonite | 2.94 | Calcium carbonate |
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Pezzotaite | 2.90-3.10 | Caesium beryllium lithium alum. silicate |
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Nephrite Jade | 2.90-3.03 | Calcium aluminum iron silicate |
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Datolite | 2.90-3.00 | Calcium boron hydroxide nesosilicate |
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Chrome Tourmaline |
2.82-3.32 | Soldium lithium boron silicate with chromium |
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Paraiba Tourmaline |
2.82-3.32 | Soldium lithium boron silicate with copper |
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Rubellite Tourmaline |
2.82-3.32 | Soldium lithium boron silicate |
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Tourmaline | 2.82-3.32 | Soldium lithium boron silicate |
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Prehnite | 2.82-2.94 | Basic calcium aluminum silicate |
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Lepidolite | 2.80-2.90 | Potassium aluminum lithium silicate |
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Sugilite | 2.76-2.80 | Pot. sodium lith. iron manganese alum. silicate |
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Ammolite (Korite) |
2.75-2.80 | Calcium carbonate |
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Eudialyte | 2.74-2.98 | Zirconium silicate |
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Larimar (Pectolite) |
2.74-2.88 | Sodium calcium inosilicate hydroxide |
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Calcite | 2.69-2.71 | Calcium carbonate |
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Cobaltocalcite | 2.69-2.71 | Calcium carbonate & cobalt |
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Aquamarine | 2.68-2.74 | Aluminum beryllium silicate |
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Emerald | 2.67-2.78 | Aluminum beryllium silicate |
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Golden Beryl | 2.66-2.87 | Aluminum beryllium silicate |
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Goshenite Beryl |
2.66-2.87 | Aluminum beryllium silicate |
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Morganite | 2.66-2.87 | Aluminum beryllium silicate |
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Red Beryl (Bixbite) |
2.66-2.87 | Aluminum beryllium silicate |
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Labradorite | 2.65-2.75 | Sodium calcium aluminum silicate |
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Andesine | 2.65-2.69 | Sodium calcium aluminum silicate |
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Amethyst | 2.65 | Silicon dioxide |
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Ametrine | 2.65 | Silicon dioxide |
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Citrine | 2.65 | Silicon dioxide |
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Rock Crystal | 2.65 | Silicon dioxide |
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Rose Quartz |
2.65 | Silicon dioxide |
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Smoky Quartz |
2.65 | Silicon dioxide |
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Aventurine | 2.64-2.69 | Silicon dioxide |
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Oligoclase | 2.62-2.67 | Sodium calcium aluminum silicate |
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Sunstone | 2.62-2.65 | Sodium calcium aluminum silicate |
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Pearl | 2.60-2.85 | Calcium carbonate |
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Coral | 2.60-2.70 | Calcium carbonate |
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Agate | 2.60-2.64 | Silicon dioxide |
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Jasper | 2.58-2.91 | Silicon dioxide |
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Iolite | 2.58-2.66 | Magnesium aluminum silicate |
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Bloodstone | 2.58-2.64 | Silicon dioxide |
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Carnelian | 2.58-2.64 | Silicon dioxide |
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Chalcedony | 2.58-2.64 | Silicon dioxide |
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Chrome Chalcedony |
2.58-2.64 | Silicon dioxide |
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Chrysoprase | 2.58-2.64 | Silicon dioxide |
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Gem Silica | 2.58-2.64 |
Silicon |
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Onyx | 2.58-2.64 | Silicon dioxide |
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Scapolite | 2.57-2.74 | Sodium calcium aluminum silicate |
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Moonstone | 2.56-2.59 | Potassium aluminum silicate |
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Amazonite | 2.56-2.58 | Potassium aluminum silicate |
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Orthoclase | 2.56-.2.58 | Potassium aluminum silicate |
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Charoite | 2.54-2.78 | Complex alkaline calcic silicate |
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Williamsite | 2.51-2.63 | Hydrous magnesium iron phyllosilicate |
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Poudretteite | 2.51-2.53 | Potassium sodium boron silicate |
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Lapis Lazuli | 2.50-3.00 | Sodim calcium aluminium silicate |
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Howlite | 2.45-2.58 | Calcium borosilicate hydroxide |
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Carletonite | 2.45 | Hydrated pot. sodium calcium carb. silicate |
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Hauyne | 2.40-2.50 | Sodium aluminum silicate |
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Petalite | 2.40 | Lithium aluminium phyllosilicate |
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Obsidian | 2.35-2.60 | Siliceous glassy rock |
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Hambergite | 2.35 | Beryllium borate |
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Moldavite | 2.32-2.38 | Silicon dioxide compound with other minerals |
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Turquoise | 2.31-2.84 | Hydrated copper aluminum phosphate |
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Hackmanite | 2.14-2.40 | Sodium aluminum chloride silicate |
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Sodalite | 2.14-2.40 | Sodium aluminum chloride silicate |
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Chrysocolla | 2.00-2.40 | Hydrous copper silicate |
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Mexican Fire Opal |
1.88-2.50 | Hydrous silicon dioxide |
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Opal | 1.88-2.50 | Hydrous silicon dioxide |
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Ulexite | 1.65-1.95 | Hydrated sodium calcium borate hydroxide |
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Jet | 1.19-1.35 | Carbon (bituminous coal) |
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Amber | 1.05-1.09 | Fossilised organic resin |
Different types of gemstones vary in density, and this fact is of interest to both gemologists and consumers.
It is important for consumers to understand gemstone density because buying colored gems by carat weight alone can lead to unexpected results. Though it is common to buy diamonds by weight, colored gems vary greatly by density. For example, a 1 carat sapphire is significantly smaller than a 1 carat diamond, while a 1 carat opal is significantly larger.
In gemology, the density or specific gravity of a gemstone is computed as the ratio of the density of the material to the density of water. The density is expressed as a number which indicates how much heavier the gemstone is compared to an equal volume of water.
Most gemstone varieties are 2 to 4 times denser than a equal volume of water. But the range is quite wide -- from 8 for cinnabar to 1 for amber. Diamond, at 3.50 to 3.53, falls approximately in the middle.
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