1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
3.10-3.203.30-3.40
1
7.18
1.5 Fracture
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Conchoidal, Brittle, Conchoidal
1.6 Cleavage
Poor to good on (001)
{010} perfect, {110} distinct, {100} in traces
1.7 Mohs Hardness
1.8 Chemical Composition
(Mg,Fe) 5(SiO 4) 2(F,OH) 2Ulrich Henn and Claudio C.
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references