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