Achroite and Alunite Physical Properties
Tenacity
Not Available
Brittle
Solubility
Not Available
Soluble
Durability
Not Available
Not Available
Specific Gravity
2.90-3.40
2.6-2.9
Fracture
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, Uneven
Cleavage
Not Available
On {0001}, perfect
Mohs Hardness
7-7.5
3.5-4
Chemical Composition
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) Formula given for elbaite.
KAl3(SO4)2(OH)6
Achroite and Alunite Chemical Formula
While comparing Achroite 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 Achroite and Alunite chemical formula.
- Chemical formula of Achroite- Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) Formula given for elbaite.
- Chemical formula of Alunite- KAl3(SO4)2(OH)6
Achroite and Alunite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Achroite and Alunite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Achroite and Alunite Optical Properties during the identification of gemstone. Specific gravity of Achroite is 2.6-2.9 whereas that of Alunite is 2.6-2.9.