Alunite and Dravite Physical Properties
Tenacity
Brittle
Not Available
Solubility
Soluble
Not Available
Durability
Not Available
Not Available
Specific Gravity
2.6-2.9
3.03-3.18
Fracture
Conchoidal, Uneven
Uneven, Uneven, Irregular, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Cleavage
On {0001}, perfect
{???} Indistinct
Mohs Hardness
3.5-4
7-7.5
Chemical Composition
KAl3(SO4)2(OH)6
Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
Alunite and Dravite Chemical Formula
While comparing Alunite and Dravite 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 Dravite chemical formula.
- Chemical formula of Alunite- KAl3(SO4)2(OH)6
- Chemical formula of Dravite- Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
Alunite and Dravite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Alunite and Dravite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Alunite and Dravite Optical Properties during the identification of gemstone. Specific gravity of Alunite is 3.03-3.18 whereas that of Dravite is 3.03-3.18.