Schorl and Black Opal Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.18-3.22
  
1.97-2.22
  
Fracture
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
  
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Cleavage
{1011} Indistinct
  
Not Available
  
Mohs Hardness
Not Available
  
6-6.5
  
Chemical Composition
Na(Fe2+3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
  
SiO 2 + H 2OUlrich Henn and Claudio C.
  
Schorl and Black Opal Chemical Formula
While comparing Schorl and Black Opal 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 Schorl and Black Opal chemical formula.
- Chemical formula of Schorl- Na(Fe2+3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
Schorl and Black Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Schorl and Black Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Schorl and Black Opal Optical Properties during the identification of gemstone. Specific gravity of Schorl is 1.97-2.22 whereas that of Black Opal is 1.97-2.22.