Achroite and Ettringite Physical Properties
Solubility
-
Partially soluble in water
Specific Gravity
2.90-3.40
1.77
Fracture
Uneven, ConchoidalWalter Schumann
-
Cleavage
Indiscernible
Perfect on {10 1 0}
Mohs Hardness
7-7.5
2-2.5
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.
Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
Achroite and Ettringite Chemical Formula
While comparing Achroite and Ettringite 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 Ettringite 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 Ettringite- Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
Achroite and Ettringite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Achroite and Ettringite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Achroite and Ettringite Optical Properties during the identification of gemstone. Specific gravity of Achroite is 1.77 whereas that of Ettringite is 1.77.