Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.7-3.82.74-2.76
1
7.18
👆🏻
Fracture
Subconchoidal, Conchoidal
Uneven
Cleavage
Distinct on {010}
{010} Perfect, {001} Distinct
Mohs Hardness
7-7.53.5-4
2
10
👆🏻
Chemical Composition
(Fe,Mg,Zn) 2Al 9(Si,Al) 4O 22(OH) 2Ulrich Henn and Claudio C.
Fe3+ PO 4 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)