Black Opal and Erythrite Physical Properties
Tenacity
Not Available
Sectile
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
1.97-2.22
3.06
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Sectile Curved shavings or scrapings produced by a knife blade, (e.g. graphite).
Cleavage
Not Available
Perfect on {010}; poor on {100} and { 1 02}.
Mohs Hardness
6-6.5
Not Available
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
Co3(AsO4)2•8(H2O)
Black Opal and Erythrite Chemical Formula
While comparing Black Opal and Erythrite 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 Erythrite chemical formula.
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Erythrite- Co3(AsO4)2•8(H2O)
Black Opal and Erythrite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Black Opal and Erythrite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Erythrite Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 3.06 whereas that of Erythrite is 3.06.