Ettringite and Common Opal Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Partially soluble in water
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.77
  
1.98-2.50
  
Fracture
Not Available
  
Conchoidal, Conchoidal, Gemstones of the world (2001)
  
Cleavage
Perfect on {10 1 0}
  
Not Available
  
Mohs Hardness
2-2.5
  
5.5-6.5
  
Chemical Composition
Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
  
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
  
Ettringite and Common Opal Chemical Formula
While comparing Ettringite and Common 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 Ettringite and Common Opal chemical formula.
- Chemical formula of Ettringite- Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Ettringite and Common Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Ettringite and Common Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Ettringite and Common Opal Optical Properties during the identification of gemstone. Specific gravity of Ettringite is 1.98-2.50 whereas that of Common Opal is 1.98-2.50.