Lazurite and Alunite Physical Properties
Tenacity
Brittle
  
Brittle
  
Solubility
Soluble
  
Soluble
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.75
  
2.6-2.9
  
Fracture
Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
  
Conchoidal, Uneven
  
Cleavage
Imperfect on {110}
  
On {0001}, perfect
  
Mohs Hardness
5.5
  
3.5-4
  
Chemical Composition
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
  
KAl3(SO4)2(OH)6
  
Lazurite and Alunite Chemical Formula
While comparing Lazurite and Alunite 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 Lazurite and Alunite chemical formula.
- Chemical formula of Lazurite- (Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
- Chemical formula of Alunite- KAl3(SO4)2(OH)6
Lazurite and Alunite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Lazurite and Alunite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Lazurite and Alunite Optical Properties during the identification of gemstone. Specific gravity of Lazurite is 2.6-2.9 whereas that of Alunite is 2.6-2.9.