Blue John and Petalite Physical Properties
Tenacity
Not Available
Brittle
Solubility
Not Available
insoluble
Durability
Not Available
Not Available
Specific Gravity
3.00-3.25
2.40
Fracture
Not Available
Subconchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
Cleavage
Not Available
Perfect on {001}, poor on {201} with 38.5° angle between the two
Mohs Hardness
Not Available
6-6.5
Chemical Composition
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Blue John and Petalite Chemical Formula
While comparing Blue John 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 Blue John and Petalite chemical formula.
- Chemical formula of Blue John- CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Petalite- LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Blue John and Petalite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Blue John and Petalite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Blue John and Petalite Optical Properties during the identification of gemstone. Specific gravity of Blue John is 2.40 whereas that of Petalite is 2.40.