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