Goethite and Opal Physical Properties
Tenacity
Not Available
BrittleWalter Schumann
Solubility
HCl soluble
hot salt water
Durability
Not Available
Not Available
Specific Gravity
4.27-4.29
1.98-2.25
Fracture
Uneven, torn surfaces, (e.g. fractured metals)., Uneven, Gemstones (2009), torn surfaces, (e.g. fractured metals).
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
Cleavage
Perfect {010}
None
Mohs Hardness
5-5.5
5-6.5
Chemical Composition
FeO(OH)Arthur Thomas , Gemstones (2009)
SiO2 · nH2O
Goethite and Opal Chemical Formula
While comparing Goethite and 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 Opal chemical formula.
- Chemical formula of Goethite- FeO(OH)Arthur Thomas , Gemstones (2009)
- Chemical formula of Opal- SiO2 · nH2O
Goethite and Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Goethite and Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Goethite and Opal Optical Properties during the identification of gemstone. Specific gravity of Goethite is 1.98-2.25 whereas that of Opal is 1.98-2.25.