Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Subconchoidal, Conchoidal
(Fe,Mn)Ta 2O 6Walter Schumann , Gemstones of the world (2001) More from other references
slightly water soluble and in hot hydrochloric acid
Subconchoidal, Uneven, ConchoidalWalter Schumann
Octahedral, perfect on {111}, parting on {011}