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