Calcite and Gypsum Physical Properties
Tenacity
Brittle
  
Flexible
  
Solubility
Soluble
  
Soluble
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.67-2.73
  
2.20-2.40
  
Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
  
Conchoidal, Splintery, Fibrous, UnevenArthur Thomas, Gemstones (2009)
  
Cleavage
Perfect on [10 1 1] three directions with angle of 74° 55
  
Perfect on {010}, distinct on {100}
  
Mohs Hardness
3
  
2
  
Chemical Composition
CaCO 3Ulrich Henn and Claudio C.
  
CaSO 4 -2(H 2O)Arthur Thomas , Gemstones (2009)
  
Calcite and Gypsum Chemical Formula
While comparing Calcite 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 Calcite and Gypsum chemical formula.
- Chemical formula of Calcite- CaCO 3Ulrich Henn and Claudio C.
- Chemical formula of Gypsum- CaSO 4 -2(H 2O)Arthur Thomas , Gemstones (2009)
Calcite and Gypsum Specific Gravity
Another important criteria for qualitative analysis of gemstones is Calcite and Gypsum Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Calcite and Gypsum Optical Properties during the identification of gemstone. Specific gravity of Calcite is 2.20-2.40 whereas that of Gypsum is 2.20-2.40.