Astrophyllite and Achroite Physical Properties
Specific Gravity
3.2-3.4
2.90-3.40
Fracture
Uneven
Uneven, ConchoidalWalter Schumann
Cleavage
Perfect on [001] imperfect on [100]
Indiscernible
Chemical Composition
(K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)
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.
Astrophyllite and Achroite Chemical Formula
While comparing Astrophyllite 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 Astrophyllite and Achroite 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 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.
Astrophyllite and Achroite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Astrophyllite and Achroite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Astrophyllite and Achroite Optical Properties during the identification of gemstone. Specific gravity of Astrophyllite is 2.90-3.40 whereas that of Achroite is 2.90-3.40.