Goethite and Sillimanite Physical Properties
Tenacity
Not Available
Tough
Solubility
HCl soluble
Not Available
Durability
Not Available
Not Available
Specific Gravity
4.27-4.29
3.20-3.26
Fracture
Uneven, torn surfaces, (e.g. fractured metals)., Uneven, Gemstones (2009), torn surfaces, (e.g. fractured metals).
Splintery
Cleavage
Perfect {010}
{010} perfect
Mohs Hardness
5-5.5
6-7.5
Chemical Composition
FeO(OH)Arthur Thomas , Gemstones (2009)
Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Goethite and Sillimanite Chemical Formula
While comparing Goethite and Sillimanite 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 Sillimanite chemical formula.
- Chemical formula of Goethite- FeO(OH)Arthur Thomas , Gemstones (2009)
- Chemical formula of Sillimanite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Goethite and Sillimanite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Goethite and Sillimanite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Goethite and Sillimanite Optical Properties during the identification of gemstone. Specific gravity of Goethite is 3.20-3.26 whereas that of Sillimanite is 3.20-3.26.