Black Opal and Emerald Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Hard
  
Specific Gravity
1.97-2.22
  
2.67-2.78
  
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
  
Cleavage
Not Available
  
Imperfect on the [0001]
  
Mohs Hardness
6-6.5
  
7.5-8
  
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
  
Be3Al2SiO6
  
Black Opal and Emerald Chemical Formula
While comparing Black Opal and Emerald 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 Black Opal and Emerald chemical formula.
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Emerald- Be3Al2SiO6
Black Opal and Emerald Specific Gravity
Another important criteria for qualitative analysis of gemstones is Black Opal and Emerald Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Emerald Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 2.67-2.78 whereas that of Emerald is 2.67-2.78.