Astrophyllite and Biotite Physical Properties

Astrophyllite and Biotite Chemical Formula

While comparing Astrophyllite and Biotite 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 Astrophyllite and Biotite chemical formula.

• Chemical formula of Astrophyllite- (K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)
• Chemical formula of Biotite- K(Mg,Fe++)3[AlSi3O10(OH,F)2

Astrophyllite and Biotite Specific Gravity

Another important criteria for qualitative analysis of gemstones is Astrophyllite and Biotite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Astrophyllite and Biotite Optical Properties during the identification of gemstone. Specific gravity of Astrophyllite is 2.7-3.3 whereas that of Biotite is 2.7-3.3.