Goethite and Common Opal Physical Properties
Tenacity
Not Available
Not Available
Solubility
HCl soluble
Not Available
Durability
Not Available
Not Available
Specific Gravity
4.27-4.29
1.98-2.50
Fracture
Uneven, torn surfaces, (e.g. fractured metals)., Uneven, Gemstones (2009), torn surfaces, (e.g. fractured metals).
Conchoidal, Conchoidal, Gemstones of the world (2001)
Cleavage
Perfect {010}
Not Available
Mohs Hardness
5-5.5
5.5-6.5
Chemical Composition
FeO(OH)Arthur Thomas , Gemstones (2009)
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Goethite and Common Opal Chemical Formula
While comparing Goethite and Common 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 Common Opal chemical formula.
- Chemical formula of Goethite- FeO(OH)Arthur Thomas , Gemstones (2009)
- Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Goethite and Common Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Goethite and Common Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Goethite and Common Opal Optical Properties during the identification of gemstone. Specific gravity of Goethite is 1.98-2.50 whereas that of Common Opal is 1.98-2.50.