Howlite and Polyhalite Physical Properties
Tenacity
Not Available
  
Brittle
  
Solubility
Not Available
  
Soluble
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.45-2.58
  
2.78
  
Fracture
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
  
Conchoidal, Brittle
  
Cleavage
None
  
Perfect on {10 1 }; parting on {010}
  
Mohs Hardness
3-3.5
  
3.5
  
Chemical Composition
Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
  
Not Available
  
Howlite and Polyhalite Chemical Formula
While comparing Howlite and Polyhalite 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 Howlite and Polyhalite chemical formula.
- Chemical formula of Howlite- Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
>
Howlite and Polyhalite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Howlite and Polyhalite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Howlite and Polyhalite Optical Properties during the identification of gemstone. Specific gravity of Howlite is 2.78 whereas that of Polyhalite is 2.78.