Phenakite and Black Opal Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.90-2.98
  
1.97-2.22
  
Fracture
Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001), Brittle
  
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
  
Not Available
  
Mohs Hardness
7.5-8
  
6-6.5
  
Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
  
SiO 2 + H 2OUlrich Henn and Claudio C.
  
Phenakite and Black Opal Chemical Formula
While comparing Phenakite 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 Phenakite and Black Opal chemical formula.
- Chemical formula of Phenakite- Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
Phenakite and Black Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Phenakite and Black Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Phenakite and Black Opal Optical Properties during the identification of gemstone. Specific gravity of Phenakite is 1.97-2.22 whereas that of Black Opal is 1.97-2.22.