Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.25-3.452.9-3.5
1
7.18
👆🏻
Fracture
Conchoidal, Uneven
Conchoidal
Cleavage
Good on {110}
{110} Perfect, {???} Distinct, {???} Distinct
Mohs Hardness
6.55.5-6
2
10
👆🏻
Chemical Composition
Mg 3Al 6(Si,Al,B) 5O 21(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Mg,Fe2+ ) 2(Mg,Fe2+ ) 5Si 8O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)