Common Opal and Aragonite Physical Properties
Tenacity
Not Available
  
Brittle
  
Solubility
Not Available
  
Dilute acid
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.50
  
2.93-2.96
  
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001)
  
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
  
Cleavage
Not Available
  
Distinct on {010}, imperfect {110} and {011}
  
Mohs Hardness
5.5-6.5
  
3.5-4
  
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
  
CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
  
Common Opal and Aragonite Chemical Formula
While comparing Common Opal and Aragonite 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 Common Opal and Aragonite chemical formula.
- Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
- Chemical formula of Aragonite- CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Common Opal and Aragonite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Common Opal and Aragonite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Common Opal and Aragonite Optical Properties during the identification of gemstone. Specific gravity of Common Opal is 2.93-2.96 whereas that of Aragonite is 2.93-2.96.