Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.60-2.645.2
1
7.18
👆🏻
Fracture
Uneven, Splintery, Conchoidal
Subconchoidal, Conchoidal
Cleavage
Absent
Good in one direction
Mohs Hardness
6.5-76-6.5
2
10
👆🏻
Chemical Composition
SiO 2Arthur Thomas , Gemstones (2009)
(Fe,Mn)Ta 2O 6Walter Schumann , Gemstones of the world (2001) More from other references