Calcite and Precious Opal Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Soluble
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.67-2.73
  
1.98-2.25
  
Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
  
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
  
Cleavage
Perfect on [10 1 1] three directions with angle of 74° 55
  
Not Available
  
Mohs Hardness
3
  
5-6.5
  
Chemical Composition
CaCO 3Ulrich Henn and Claudio C.
  
SiO 2 · nH 2OGemdat.org , Management Team (2012)
  
Calcite and Precious Opal Chemical Formula
While comparing Calcite and Precious Opal 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 Precious Opal chemical formula.
- Chemical formula of Calcite- CaCO 3Ulrich Henn and Claudio C.
- Chemical formula of Precious Opal- SiO 2 · nH 2OGemdat.org , Management Team (2012)
Calcite and Precious Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Calcite and Precious Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Calcite and Precious Opal Optical Properties during the identification of gemstone. Specific gravity of Calcite is 1.98-2.25 whereas that of Precious Opal is 1.98-2.25.