Afghanite and Alunite Physical Properties
Tenacity
Not Available
Brittle
Solubility
Not Available
Soluble
Durability
Not Available
Not Available
Specific Gravity
2.55-2.65
2.6-2.9
Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle, Conchoidal, Brittle
Conchoidal, Uneven
Cleavage
Perfect {10 1 0}
On {0001}, perfect
Mohs Hardness
5.5-6
3.5-4
Chemical Composition
(Na,Ca,K) 8(Si,Al) 12O 24(SO 4,Cl,CO 3) 3(H 2O)Arthur Thomas , Gemstones (2009)
KAl3(SO4)2(OH)6
Afghanite and Alunite Chemical Formula
While comparing Afghanite 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 Afghanite and Alunite chemical formula.
- Chemical formula of Afghanite- (Na,Ca,K) 8(Si,Al) 12O 24(SO 4,Cl,CO 3) 3(H 2O)Arthur Thomas , Gemstones (2009)
- Chemical formula of Alunite- KAl3(SO4)2(OH)6
Afghanite and Alunite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Afghanite and Alunite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Afghanite and Alunite Optical Properties during the identification of gemstone. Specific gravity of Afghanite is 2.6-2.9 whereas that of Alunite is 2.6-2.9.