1 Physical Properties
1.1 Tenacity
Very brittle
Not Available
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.5 Fracture
Conchoidal, Brittle, Conchoidal
Uneven
2.6 Cleavage
{010} perfect, {110} distinct, {100} in traces
None
2.7 Mohs Hardness
2.11 Chemical Composition
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Fe+++,Al)25(PO4)17O6(OH)12•75(H2O)