Andalusite and Purpurite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.05-3.21
  
3.2-3.4
  
Fracture
Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
  
Uneven, UnevenArthur Thomas, Gemstones (2009), Brittle
  
Cleavage
Good on {110}, poor on {100}
  
[100] [001] perfect
  
Mohs Hardness
7.5
  
4-4.5
  
Chemical Composition
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
  
MnPO 4Walter Schumann , Gemstones of the world (2001) More from other references
  
Andalusite and Purpurite Chemical Formula
While comparing Andalusite and Purpurite 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 Andalusite and Purpurite chemical formula.
- Chemical formula of Andalusite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
- Chemical formula of Purpurite- MnPO 4Walter Schumann , Gemstones of the world (2001) More from other references
Andalusite and Purpurite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Andalusite and Purpurite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Andalusite and Purpurite Optical Properties during the identification of gemstone. Specific gravity of Andalusite is 3.2-3.4 whereas that of Purpurite is 3.2-3.4.