Achroite and Sillimanite Physical Properties
Tenacity
Not Available
Tough
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
2.90-3.40
3.20-3.26
Fracture
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
Splintery
Cleavage
Not Available
{010} perfect
Mohs Hardness
7-7.5
6-7.5
Chemical Composition
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.
Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Achroite and Sillimanite Chemical Formula
While comparing Achroite and Sillimanite 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 Achroite and Sillimanite chemical formula.
- 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.
- Chemical formula of Sillimanite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Achroite and Sillimanite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Achroite and Sillimanite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Achroite and Sillimanite Optical Properties during the identification of gemstone. Specific gravity of Achroite is 3.20-3.26 whereas that of Sillimanite is 3.20-3.26.