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
1.5 Fracture
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009)
UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001)
1.6 Cleavage
Good in one direction
{100} Perfect, {001} Perfect
1.7 Mohs Hardness
1.8 Chemical Composition
(Fe,Mn)Ta 2O 6Walter Schumann , Gemstones of the world (2001) More from other references
Na(Mn2+ ,Ca) 2Si 3O 8(OH)Michael OâDonoghue , Gems, Sixth Edition (2006)