Opal and Aragonite Physical Properties
Tenacity
BrittleWalter Schumann
Brittle
Solubility
hot salt water
Dilute acid
Durability
Not Available
Not Available
Specific Gravity
1.98-2.25
2.93-2.96
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Cleavage
None
Distinct on {010}, imperfect {110} and {011}
Mohs Hardness
5-6.5
3.5-4
Chemical Composition
SiO2 · nH2O
CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Opal and Aragonite Chemical Formula
While comparing 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 Opal and Aragonite chemical formula.
- Chemical formula of Opal- SiO2 · nH2O
- Chemical formula of Aragonite- CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Opal and Aragonite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Opal and Aragonite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Opal and Aragonite Optical Properties during the identification of gemstone. Specific gravity of Opal is 2.93-2.96 whereas that of Aragonite is 2.93-2.96.