Obsidian and Apatite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.35-2.60
  
3.16-3.23
  
Fracture
Conchoidal, ConchoidalWalter Schumann, Conchoidal
  
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
  
Cleavage
Not Available
  
[0001] indistinct, [1010] indistinct
  
Mohs Hardness
5-5.5
  
5
  
Chemical Composition
Not Available
  
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references
  
Obsidian and Apatite Chemical Formula
While comparing Obsidian and Apatite 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 Obsidian and Apatite chemical formula.
>- Chemical formula of Apatite- Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references
Obsidian and Apatite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Obsidian and Apatite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Obsidian and Apatite Optical Properties during the identification of gemstone. Specific gravity of Obsidian is 3.16-3.23 whereas that of Apatite is 3.16-3.23.