Common Opal and Sillimanite Physical Properties
Tenacity
Not Available
Tough
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
1.98-2.50
3.20-3.26
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001)
Splintery
Cleavage
Not Available
{010} perfect
Mohs Hardness
5.5-6.5
6-7.5
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Common Opal and Sillimanite Chemical Formula
While comparing Common Opal 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 Common Opal and Sillimanite chemical formula.
- Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
- Chemical formula of Sillimanite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Common Opal and Sillimanite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Common Opal and Sillimanite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Common Opal and Sillimanite Optical Properties during the identification of gemstone. Specific gravity of Common Opal is 3.20-3.26 whereas that of Sillimanite is 3.20-3.26.