Opal and Tourmaline Physical Properties
Tenacity
BrittleWalter Schumann
  
Not Available
  
Solubility
hot salt water
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.25
  
2.85-3.35
  
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
  
Uneven, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
  
Cleavage
None
  
Indistinct
  
Mohs Hardness
5-6.5
  
7-7.5
  
Chemical Composition
SiO2 · nH2O
  
Tourmaline is a series of several different minerals with unique chemical formulas. See The chemical formula of Tourmaline for details.
  
Opal and Tourmaline Chemical Formula
While comparing Opal 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 Opal and Tourmaline chemical formula.
- Chemical formula of Opal- SiO2 · nH2O
- Chemical formula of Tourmaline- Tourmaline is a series of several different minerals with unique chemical formulas. See The chemical formula of Tourmaline for details.
Opal and Tourmaline Specific Gravity
Another important criteria for qualitative analysis of gemstones is Opal and Tourmaline Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Opal and Tourmaline Optical Properties during the identification of gemstone. Specific gravity of Opal is 2.85-3.35 whereas that of Tourmaline is 2.85-3.35.