Achroite and Gahnite Physical Properties
Specific Gravity
2.90-3.40
4.00-4.62
Fracture
Uneven, ConchoidalWalter Schumann
Conchoidal, Uneven
Cleavage
Indiscernible
Indistinct parting on [111]
Mohs Hardness
7-7.5
7.5-8
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.
ZnAl 2O 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Achroite and Gahnite Chemical Formula
While comparing Achroite and Gahnite 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 Gahnite 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 Gahnite- ZnAl 2O 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Achroite and Gahnite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Achroite and Gahnite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Achroite and Gahnite Optical Properties during the identification of gemstone. Specific gravity of Achroite is 4.00-4.62 whereas that of Gahnite is 4.00-4.62.