Ettringite and Achroite Physical Properties

Ettringite and Achroite Chemical Formula

While comparing Ettringite and Achroite 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 Ettringite and Achroite chemical formula.

• Chemical formula of Ettringite- Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael O’Donoghue , Gems, Sixth Edition (2006)
• 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.

Ettringite and Achroite Specific Gravity

Another important criteria for qualitative analysis of gemstones is Ettringite and Achroite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Ettringite and Achroite Optical Properties during the identification of gemstone. Specific gravity of Ettringite is 2.90-3.40 whereas that of Achroite is 2.90-3.40.