Willemite and Black Opal Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.89-4.18
  
1.97-2.22
  
Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven
  
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Cleavage
{0001}, {11 2 0} imperfect
  
Not Available
  
Mohs Hardness
5.5
  
6-6.5
  
Chemical Composition
Zn 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
  
SiO 2 + H 2OUlrich Henn and Claudio C.
  
Willemite and Black Opal Chemical Formula
While comparing Willemite 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 Willemite and Black Opal chemical formula.
- Chemical formula of Willemite- Zn 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
Willemite and Black Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Willemite and Black Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Willemite and Black Opal Optical Properties during the identification of gemstone. Specific gravity of Willemite is 1.97-2.22 whereas that of Black Opal is 1.97-2.22.