1 Physical Properties
1.1 Tenacity
Not Available
Not Available
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
3.26-3.363.76-3.77
1
7.18
1.5 Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
1.6 Cleavage
Good on {100}
{110} Perfect, {110} Perfect
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
(Fe,Mn) 7Si 7O 21Ulrich Henn and Claudio C.