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Gemstone's specific gravity

Specific gravity, the abbreviated is SG, is the meatured that comparing about the gemstone's weight when weighted in the air with weighted suspennded in pure water. Because specific gravity varies with chemical composition and crystal structure type.The specific gravity is a ratio which can be used for indentifying gemstones. But this method can not be used for identified gemstone alone. But the specific gravity can help in reducing the amount kind of gemstone of possibilities.

The table below is the list gemstone's specifict gravity that arranged from the gemstone in increasing order.

Gemstone type

Specific gravity

Chemical Composition

Crystal Structure

Amber

1.05 – 1.10

Oxygenated hydrocarbon (variable)

Amorphous

Chrysocolla

1.9 – 2.4

Hydrous copper silicate

Monoclinic

Opal ex. Fire opal, Moss opal, Doublet opal and Boulder opal

1.98 – 2.5

Hydrous silicon dioxide

Amorphous

Hackmanite

2.14 – 2.40

Sodium aluminum silicate chloride

Cubic

Sodalite

2.14 – 2.40

Sodium aluminum silicate chloride

Cubic

Tourmaline ex. Rubellite, Paraiba, Chrome etc.

2.28 – 3.32

Silicate compounded with aluminium, iron, magnesium, sodium, lithium, or potassium.

Trigonal

Turquoise

2.31 – 2.84

Hydrated copper aluminum phosphate

Triclinic

Moldavite

2.32 – 2.38

Silicon dioxide + aluminum oxide

Amorphous

Hambergite

2.35

Beryllium borate

Orthorhombic

Obsidian

2.35 – 2.60

Siliceous glassy rock

Amorphous

Variscite

2.42 – 2.58

Hydrous aluminum phosphate

Orthorhombic

Serpentine

2.44 – 2.62

Basic magnesium silicate

Microcrystalline

Howlite

2.45 – 2.58

Calcium borosilicate hydroxide

Monoclinic

Lapis lazuli

2.5 - 3

Sodium calcium aluminum silicate

Cubic

Maw sit sit

2.5 – 3.5

Rock containing variable amounts of kosmochlor, jadeite and albite

Rock

Jasper

2.5 – 2.9

Silicon dioxide

Trigonal

Charoite

2.54 – 2.78

Complex silicate containing phosphorus, calcium, and sodium

Monochinic

Seraphinite

2.55 – 2.75

Magnesium iron aluminum silicate hyroxide

Monochinic

Amazonite

2.56 – 2.58

Potassium aluminum silicate

Triclinic

Orthoclase

2.56 – 2.58

Potassium aluminum silicate

Monochinic

Moonstone

2.56 – 2.59

Potassium aluminum silicate

Monochinic

Scapolite

2.57 – 2.74

Sodium calcium aluminium silicate

Tetragonal

Chrysophase

2.58 – 2.64

Silicon dioxide

Trigonal

Bloodstone

2.58 – 2.64

Silicon dioxide

Trigonal

Agate & Carnelian

2.58 – 2.64

Silicon dioxide

Trigonal

Peanut wood

2.58 – 2.91

Silicon dioxide

Trigonal

Rose quartz cat’s eye

2.58 – 2.64

Silicon dioxide

Hexagonal

Chalcedony

2.58 – 2.64

Silicon dioxide

Trigonal

Tiger’s eye

2.58 – 2.64

Silicon dioxide

Trigonal

Iolite

2.58 – 2.66

Magnesium aluminum silicate

Orthorhombic

Coral

2.6 – 2.7

Calcium carbonate

Trigonal

Pietersite

2.6

Silicon dioxide

Aggregate

Fossil coral

2.6 – 2.7

Silicon dioxide

Trigonal

Agate geode

2.6 – 2.64

Silicon dioxide

Trigonal

Pearl

2.6 – 2.85

Calcium carbonate

Orthorhombic

Sunstone

2.62 – 2.65

Sodium calcium aluminium silicate

Triclinic

Aventurine

2.64 – 2.69

Silicon dioxide

Trigonal

Quartz

2.65

Silicon dioxide

Trigonal

Strawberry quartz

2.65

Silocon dioxide with iron oxide inclusions

Trigonal

Amethyst

2.65

Silicon dioxide

Trigonal

Quartz ex. Rose, Smoky, Cat’s eye and Mystic

2.65

Silicon dioxide

Trigonal

Labradorite

2.65 – 2.75

Sodium calcium aluminum silicate

Triclinic

Citrine

2.65

Silicon dioxide

Hexagonal

Rutile quartz

2.65

Silicon dioxide with titanium inclusions

Trigonal

Ametrine

2.65

Silicon dioxide

Trigonal

Onyx

2.65 – 2.91

Silicon dioxide

Trigonal

Andesine labradorite

2.66 – 2.68

Sodium calcium aluminum silicate

Triclinic

Beryl ex. Morganite, Goshenite etc

2.66 – 2.87

Aluminium beryllium silicate

Hexagonal

Emerald

2.66 – 2.87

Aluminium beryllium silicate

Hexagonal

Aquamarine

2.66 – 2.87

Aluminium beryllium silicate

Hexagonal

Calcite

2.69 – 2.71

Calcium carbonate

Trigonal

Larimar

2.74 – 2.88

Hydrated sodium calcium silicate with manganese

Triclinic

Ammolite

2.75 – 2.80

Mainly aragonite (with calcite, silica and pyrite)

Amorphous

Sugilite

2.76 – 2.80

Potassium sodium lithium iron manganese aluminium

Hexagonal

Verdite

2.76 - 3

Serpentine rock

Monoclinic

Lepidolite

2.8 – 2.9

Potassium lithium aluminum silicate hydroxide fluo

Monoclinic

Prehnite

2.82 – 2.94

Basic calcium aluminum silicate

Orthorhombic

Jadeite

2.90 – 3.03

Basic calcium magnesium iron silicate

Monoclinic

Nephrite jade

2.9 – 3.03

Calcium magnesium iron silicate

Monoclinic

Danburite

2.97 – 3.03

Calcium boric silicate

Orthorhombic

Nuumite

3

Rock containing gedrite and anthophyllite

Lamellar fibrous structure

Fluorite

3 – 3.25

Calcium fluoride

Cubic

Andalusite

3.05 – 3.20

Aluminium silicate

Orthorhombic

Clinohumite

3.13 – 3.75

Magnesium silicate

Monoclinic

Spodumene ex. Kunzite

3.15 – 3.21

Lithium aluminum silicate

Monoclinic

Apatite

3.16 – 3.23

Basic fluoro- and chloro-calicum phosphate

Hexagonal

Hiddenite

3.17 – 3..19

Lithium aluminum silicate

Monoclinic

Diopsie ex. Chrome, Tashmarine and star

3.22 – 3.38

Calcium magnesium silicate

Monoclinic

Sillimanite

3.23

Aluminum silicate

Orthorhombic

Malachite

3.25 – 4.10

Basic copper carbonate

Monoclinic

Dumortierite quartz

3.26 – 3.41

Aluminum borate silicate intergrown with quartz

Orthorhombic

Axinite

3.26 – 3.360

Calcium aluminum borate silicate

Triclinic

Peridot

3.28 – 3.48

Magnesium iron silicate

Orthorhombic

Hemimorphite

3.3 – 3.5

Hydrous basic zinc silicate

Orthorhombic

Diaspore or Zultanite

3.30 – 3.39

Hydrated aluminum oxide

Orthorhombic

Idocrase

3.32 – 3.47

Complex calcium aluminum silicate

Tetragonal

Ruby - Zoisite

3.35

Rock containing zoisite, ruby and hornblende

Orthorhombic

Tanzanite

3.35

Calcium aluminium silicate

Orthorhombic

Rhodonite

3.40 – 3.74

Manganese silicate

Triclinic

Rhodochrosite

3.45 – 3.70

Manganese carbonate

Trigonal

Topaz ex. Rutile, Mystic, Azotic, imperial etc.

3.49 – 3.57

Aluminum fluorsilicate

Orthorhombic

Sphene

3.52 – 3.54

Calcium titanium silicate

Monoclinic

Kyanite

3.53 – 3.70

Aluminum silicate

Triclinic

Spinel

3.54 – 3.63

Magnesium aluminium oxide

Cubic

Grossular garnet ex. Grossularite and Mali

3.57 – 3.73

Calcium aluminum silicate

Cubic

Tsavorite Garnet

3.57 – 3.73

Calcium aluminum silicate

Rhombic

Garnet ex. Pyrope and Color Change Garnet

3.62 – 3.87

Magnesium aluminum silicate

Cubic

Star garnet

3.62 – 3.87

Iron aluminum silicate

Rhombic

Hessonite Garnet

3.64 – 3.69

Calcium aluminum silicate

Cubic

Demantoid Garnet

3.7 – 4.1

Calcium iron silicate

Cubic

Melanite

3.7 – 4.1

Calcium iron silicate

Cubic

Chrysoberyl

3.70 – 3.78

Beryllium aluminium oxide

Orthorhombic

Alexandrite

3.70 – 3.78

Beryllium aluminium oxide

Orthorhombic

Azurite

3.7 – 3.9

Basic Copper Carbonate

Monoclinic

Gaspeite

3.71

Nickel magnesium iron carbonate

Trigonal

Rhodolite Garnet

3.85

Magnesium aluminum silicate

Cubic

Sphalerite

3.9 – 4.1

Zinc sulphide

Cubic

Almandite Garnet

3.93 – 4.30

Iron aluminium silicate

Cubic

Zircon

3.93 – 4.73

Zirconium silicate

Tetragonal

Sapphire

3.95 – 4.03

Aluminium oxide

Trigonal

Ruby

3.97 – 4.05

Aluminum oxide

Trigonal

Smithsonite

4.00 – 4.65

Zinc carbonate

Trigonal

Spessartite Garnet

4.12 – 4.18

Manganese aluminium silicate

Cubic

Rainbow pyrite

5 – 5.2

Iron sulphide

Cubic

Hematite

5.12 – 5.28

Iron oxide

Trigonal

Cassiterite

6.7 – 7.1

Tin oxide

Tetragonal