Dravite and Blue John Physical Properties
Tenacity
Not Available
Not Available
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
3.03-3.18
3.00-3.25
Fracture
Uneven, Uneven, Irregular, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Not Available
Cleavage
{???} Indistinct
Not Available
Mohs Hardness
7-7.5
Not Available
Chemical Composition
Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Dravite and Blue John Chemical Formula
While comparing Dravite 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 Dravite and Blue John chemical formula.
- Chemical formula of Dravite- Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
- Chemical formula of Blue John- CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Dravite and Blue John Specific Gravity
Another important criteria for qualitative analysis of gemstones is Dravite and Blue John Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Dravite and Blue John Optical Properties during the identification of gemstone. Specific gravity of Dravite is 3.00-3.25 whereas that of Blue John is 3.00-3.25.