Astrophyllite and Black Opal Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.2-3.4
  
1.97-2.22
  
Fracture
Uneven, Brittle, Metallic
  
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Cleavage
Perfect on [001] imperfect on [100]
  
Not Available
  
Mohs Hardness
3
  
6-6.5
  
Chemical Composition
(K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)
  
SiO 2 + H 2OUlrich Henn and Claudio C.
  
Astrophyllite and Black Opal Chemical Formula
While comparing Astrophyllite 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 Astrophyllite and Black Opal chemical formula.
- Chemical formula of Astrophyllite- (K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
Astrophyllite and Black Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Astrophyllite and Black Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Astrophyllite and Black Opal Optical Properties during the identification of gemstone. Specific gravity of Astrophyllite is 1.97-2.22 whereas that of Black Opal is 1.97-2.22.