Howlite and Star Sapphire Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.45-2.58
  
3.90-4.05
  
Fracture
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
  
Not Available
  
Cleavage
None
  
Not Available
  
Mohs Hardness
3-3.5
  
Not Available
  
Chemical Composition
Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
  
Al 2O 3Ulrich Henn and Claudio C.
  
Howlite and Star Sapphire Chemical Formula
While comparing Howlite and Star Sapphire 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 Star Sapphire chemical formula.
- Chemical formula of Howlite- Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
- Chemical formula of Star Sapphire- Al 2O 3Ulrich Henn and Claudio C.
Howlite and Star Sapphire Specific Gravity
Another important criteria for qualitative analysis of gemstones is Howlite and Star Sapphire Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Howlite and Star Sapphire Optical Properties during the identification of gemstone. Specific gravity of Howlite is 3.90-4.05 whereas that of Star Sapphire is 3.90-4.05.