Biotite and Achroite Physical Properties
Tenacity
Brittle
Not Available
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
2.7-3.3
2.90-3.40
Fracture
Uneven, Even, Yellow, White
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
Cleavage
Perfect on the {001}
Not Available
Mohs Hardness
2.5-3.0
7-7.5
Chemical Composition
K(Mg,Fe++)3[AlSi3O10(OH,F)2
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.
Biotite and Achroite Chemical Formula
While comparing Biotite 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 Biotite and Achroite chemical formula.
- Chemical formula of Biotite- K(Mg,Fe++)3[AlSi3O10(OH,F)2
- 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.
Biotite and Achroite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Biotite and Achroite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Biotite and Achroite Optical Properties during the identification of gemstone. Specific gravity of Biotite is 2.90-3.40 whereas that of Achroite is 2.90-3.40.