Petalite and Opal Physical Properties
Tenacity
Brittle
BrittleWalter Schumann
Solubility
insoluble
hot salt water
Durability
Not Available
Not Available
Specific Gravity
2.40
1.98-2.25
Fracture
Subconchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
Cleavage
Perfect on {001}, poor on {201} with 38.5° angle between the two
None
Mohs Hardness
6-6.5
5-6.5
Chemical Composition
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO2 · nH2O
Petalite and Opal Chemical Formula
While comparing Petalite and Opal 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 Opal chemical formula.
- Chemical formula of Petalite- LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
- Chemical formula of Opal- SiO2 · nH2O
Petalite and Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Petalite and Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Petalite and Opal Optical Properties during the identification of gemstone. Specific gravity of Petalite is 1.98-2.25 whereas that of Opal is 1.98-2.25.