Ettringite and Gypsum Physical Properties
Tenacity
Not Available
Flexible
Solubility
Partially soluble in water
Soluble
Durability
Not Available
Not Available
Specific Gravity
1.77
2.20-2.40
Fracture
Not Available
Conchoidal, Splintery, Fibrous, UnevenArthur Thomas, Gemstones (2009)
Cleavage
Perfect on {10 1 0}
Perfect on {010}, distinct on {100}
Chemical Composition
Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
CaSO 4 -2(H 2O)Arthur Thomas , Gemstones (2009)
Ettringite and Gypsum Chemical Formula
While comparing Ettringite and Gypsum physical properties, the important data you should know is its chemical composition. Since chemical formula defines the molecular structure of the crystal, most of the physical properties like color, tenacity, solubility are governed by Ettringite and Gypsum chemical formula.
- Chemical formula of Ettringite- Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Gypsum- CaSO 4 -2(H 2O)Arthur Thomas , Gemstones (2009)
Ettringite and Gypsum Specific Gravity
Another important criteria for qualitative analysis of gemstones is Ettringite and Gypsum Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Ettringite and Gypsum Optical Properties during the identification of gemstone. Specific gravity of Ettringite is 2.20-2.40 whereas that of Gypsum is 2.20-2.40.