Black Opal and Austinite Physical Properties
Tenacity
Not Available
Brittle
Solubility
Not Available
Easily soluble in cold dilute HCl
Durability
Not Available
Not Available
Specific Gravity
1.97-2.22
4.12
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Brittle, Uneven, Brittle, Uneven
Cleavage
Not Available
Good in two directions parallel to the prism faces {110}
Mohs Hardness
6-6.5
4-4.5
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
CaZn(AsO4)(OH)
Black Opal and Austinite Chemical Formula
While comparing Black Opal and Austinite 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 Black Opal and Austinite chemical formula.
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Austinite- CaZn(AsO4)(OH)
Black Opal and Austinite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Black Opal and Austinite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Austinite Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 4.12 whereas that of Austinite is 4.12.