Alunite and Cobaltite Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Soluble
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.6-2.9
  
6.3
  
Fracture
Conchoidal, Uneven
  
UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, Brittle, Metallic
  
Cleavage
On {0001}, perfect
  
{100} Good, {010} Good, {001} Good
  
Mohs Hardness
3.5-4
  
5.5
  
Chemical Composition
KAl3(SO4)2(OH)6
  
CoAsSAnthony et al , Handbook of mineralogy (2001)
  
Alunite and Cobaltite Chemical Formula
While comparing Alunite and Cobaltite 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 Alunite and Cobaltite chemical formula.
- Chemical formula of Alunite- KAl3(SO4)2(OH)6
- Chemical formula of Cobaltite- CoAsSAnthony et al , Handbook of mineralogy (2001)
Alunite and Cobaltite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Alunite and Cobaltite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Alunite and Cobaltite Optical Properties during the identification of gemstone. Specific gravity of Alunite is 6.3 whereas that of Cobaltite is 6.3.