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