Tourmaline and Onyx Physical Properties
Tenacity
Not Available
Not Available
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
2.85-3.35
2.55-2.70
Fracture
Uneven, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Not Available
Cleavage
Indistinct
Indiscernible
Mohs Hardness
7-7.5
6.5-7
Chemical Composition
Tourmaline is a series of several different minerals with unique chemical formulas. See The chemical formula of Tourmaline for details.
SiO2
Tourmaline and Onyx Chemical Formula
While comparing Tourmaline 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 Tourmaline and Onyx chemical formula.
- Chemical formula of Tourmaline- Tourmaline is a series of several different minerals with unique chemical formulas. See The chemical formula of Tourmaline for details.
- Chemical formula of Onyx- SiO2
Tourmaline and Onyx Specific Gravity
Another important criteria for qualitative analysis of gemstones is Tourmaline and Onyx Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Tourmaline and Onyx Optical Properties during the identification of gemstone. Specific gravity of Tourmaline is 2.55-2.70 whereas that of Onyx is 2.55-2.70.