Goethite and Black Opal Physical Properties
Tenacity
Not Available
Not Available
Solubility
HCl soluble
Not Available
Durability
Not Available
Not Available
Specific Gravity
4.27-4.29
1.97-2.22
Fracture
Uneven, torn surfaces, (e.g. fractured metals)., Uneven, Gemstones (2009), torn surfaces, (e.g. fractured metals).
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Cleavage
Perfect {010}
Not Available
Mohs Hardness
5-5.5
6-6.5
Chemical Composition
FeO(OH)Arthur Thomas , Gemstones (2009)
SiO 2 + H 2OUlrich Henn and Claudio C.
Goethite and Black Opal Chemical Formula
While comparing Goethite and Black 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 Goethite and Black Opal chemical formula.
- Chemical formula of Goethite- FeO(OH)Arthur Thomas , Gemstones (2009)
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
Goethite and Black Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Goethite and Black Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Goethite and Black Opal Optical Properties during the identification of gemstone. Specific gravity of Goethite is 1.97-2.22 whereas that of Black Opal is 1.97-2.22.