Tanzanite and Onyx Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Hard
  
Not Available
  
Specific Gravity
3.35
  
2.55-2.70
  
Fracture
Uneven, Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001)
  
Not Available
  
Cleavage
Perfect {010}, imperfect {100}
  
Indiscernible
  
Mohs Hardness
6.5-7
  
6.5-7
  
Chemical Composition
Ca2Al3(SiO4)3(OH)
  
SiO2
  
Tanzanite and Onyx Chemical Formula
While comparing Tanzanite and Onyx 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 Tanzanite and Onyx chemical formula.
- Chemical formula of Tanzanite- Ca2Al3(SiO4)3(OH)
- Chemical formula of Onyx- SiO2
Tanzanite and Onyx Specific Gravity
Another important criteria for qualitative analysis of gemstones is Tanzanite and Onyx Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Tanzanite and Onyx Optical Properties during the identification of gemstone. Specific gravity of Tanzanite is 2.55-2.70 whereas that of Onyx is 2.55-2.70.