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