Talc is 1
Gypsum is 2
Calcite is 3
Fluorite is 4
Apatite is 5
Feldspar is 6
Quartz is 7
Topaz is 8
Sapphire is 9
Diamond is 10
Specific gravity is the number of times heavier a gemstone of any volume
is than an equal volume of water; in other words, it is the ratio of the
density of the gemstone to the density of water.
_The 16 mineral gemstone groups listed below are highly prized for their
beauty, durability, and rarity_:
Beryl (hardness: 7.5-8 Mohs)
Beryllium aluminum silicate
Specific gravity: 2.63-2.91
_Emerald_: Intense green or bluish green
_Aquamarine_: Greenish blue or light blue
_Morganite_: Pink, purple pink, or peach
_Heliodore_: Golden yellow to golden green
_Red beryl_: Raspberry red
_Goshenite_: Colorless, greenish yellow, yellow green, brownish
Chrysoberyl (hardness: 8.5 Mohs)
Beryllium aluminum oxide
Specific gravity: 3.68-3.78
_Chrysoberyl_: transparent yellowish green to greenish yellow and pale
brown
_Alexandrite_: red in incandescent light and green in daylight
_Cat’s eye_: usually yellowish or greenish
Corundum (hardness: 9 Mohs)
Aluminum oxide
Specific gravity: 3.96-4.05
_Ruby_: Intense red
_Sapphire_: Blue
Diamond (hardness: 10 Mohs)
Carbon
Specific gravity: 3.51