Polyhalite and Fire Opal Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Soluble
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.78
  
1.97-2.22
  
Fracture
Conchoidal, Brittle
  
Conchoidal, Conchoidal, Gemstones of the world (2001)
  
Cleavage
Perfect on {10 1 }; parting on {010}
  
Not Available
  
Mohs Hardness
3.5
  
6-6.5
  
Chemical Composition
Not Available
  
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001) More from other references
  
Polyhalite and Fire Opal Chemical Formula
While comparing Polyhalite and Fire 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 Polyhalite and Fire Opal chemical formula.
>- Chemical formula of Fire Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001) More from other references
Polyhalite and Fire Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Polyhalite and Fire Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Polyhalite and Fire Opal Optical Properties during the identification of gemstone. Specific gravity of Polyhalite is 1.97-2.22 whereas that of Fire Opal is 1.97-2.22.