1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
3.26-3.365.50-5.90
1
7.18
1.5 Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
1.6 Cleavage
Good on {100}
On {10 1 0}, perfect; parting on {000 1 }
1.7 Mohs Hardness
1.8 Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)