Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Ca(Li 2Al)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
Subconchoidal, Conchoidal
(Fe,Mn)Ta 2O 6Walter Schumann , Gemstones of the world (2001) More from other references