Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.63-3.91.98-2.50
1
7.18
👆🏻
Fracture
Conchoidal, Uneven
Conchoidal
Cleavage
Indistinct
None
Mohs Hardness
7.5-85.5-6.5
2
10
👆🏻
Chemical Composition
(Mg,Fe2+ )Al 2O 4Gemdat.org , Management Team (2012) More from other references
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)