Petalite and Diaspore Physical Properties
Tenacity
Brittle
  
Very brittle
  
Solubility
insoluble
  
insoluble
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.40
  
3.30-3.40
  
Fracture
Subconchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
  
Conchoidal, Brittle, Conchoidal
  
Cleavage
Perfect on {001}, poor on {201} with 38.5° angle between the two
  
{010} perfect, {110} distinct, {100} in traces
  
Mohs Hardness
6-6.5
  
6.5-7
  
Chemical Composition
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
  
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references
  
Petalite and Diaspore Chemical Formula
While comparing Petalite and Diaspore 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 Petalite and Diaspore chemical formula.
- Chemical formula of Petalite- LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
- Chemical formula of Diaspore- AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references
Petalite and Diaspore Specific Gravity
Another important criteria for qualitative analysis of gemstones is Petalite and Diaspore Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Petalite and Diaspore Optical Properties during the identification of gemstone. Specific gravity of Petalite is 3.30-3.40 whereas that of Diaspore is 3.30-3.40.