Amethyst and Petalite Physical Properties
Tenacity
Not Available
Brittle
Solubility
insoluble in common solvents
insoluble
Durability
Not Available
Not Available
Specific Gravity
2.65
2.40
Fracture
Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
Subconchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
Cleavage
Indiscernible
Perfect on {001}, poor on {201} with 38.5° angle between the two
Chemical Composition
SiO2
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Amethyst and Petalite Chemical Formula
While comparing Amethyst and Petalite 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 Amethyst and Petalite chemical formula.
- Chemical formula of Amethyst- SiO2
- Chemical formula of Petalite- LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Amethyst and Petalite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Amethyst and Petalite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Amethyst and Petalite Optical Properties during the identification of gemstone. Specific gravity of Amethyst is 2.40 whereas that of Petalite is 2.40.