Black Opal and Achroite Physical Properties
Tenacity
Not Available
Not Available
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
1.97-2.22
2.90-3.40
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
Cleavage
Not Available
Not Available
Mohs Hardness
6-6.5
7-7.5
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) Formula given for elbaite.
Black Opal and Achroite Chemical Formula
While comparing Black Opal and Achroite 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 Achroite chemical formula.
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Achroite- Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) Formula given for elbaite.
Black Opal and Achroite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Black Opal and Achroite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Achroite Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 2.90-3.40 whereas that of Achroite is 2.90-3.40.