Sillimanite and Astrophyllite Physical Properties

Sillimanite and Astrophyllite Chemical Formula

While comparing Sillimanite and Astrophyllite 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 Sillimanite and Astrophyllite chemical formula.

• Chemical formula of Sillimanite- Al 2SiO 5Michael O’Donoghue , Gems, Sixth Edition (2006)
• Chemical formula of Astrophyllite- (K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)

Sillimanite and Astrophyllite Specific Gravity

Another important criteria for qualitative analysis of gemstones is Sillimanite and Astrophyllite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Sillimanite and Astrophyllite Optical Properties during the identification of gemstone. Specific gravity of Sillimanite is 3.2-3.4 whereas that of Astrophyllite is 3.2-3.4.