Howlite and Petalite Physical Properties
Tenacity
Not Available
Brittle
Solubility
Not Available
insoluble
Durability
Not Available
Not Available
Specific Gravity
2.45-2.58
2.40
Fracture
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Subconchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
Cleavage
None
Perfect on {001}, poor on {201} with 38.5° angle between the two
Mohs Hardness
3-3.5
6-6.5
Chemical Composition
Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Howlite and Petalite Chemical Formula
While comparing Howlite 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 Howlite and Petalite chemical formula.
- Chemical formula of Howlite- Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
- Chemical formula of Petalite- LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Howlite and Petalite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Howlite and Petalite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Howlite and Petalite Optical Properties during the identification of gemstone. Specific gravity of Howlite is 2.40 whereas that of Petalite is 2.40.