Tenacity
Very brittle
Not Available
Solubility
insoluble
Not Available
Durability
Not Available
Not Available
Specific Gravity
3.30-3.40
2.60-3.02
Fracture
Conchoidal, Brittle, Conchoidal
Uneven
Cleavage
{010} perfect, {110} distinct, {100} in traces
{001} Perfect
Mohs Hardness
6.5-7
2-2.5
Chemical Composition
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Mg,Fe2+ ) 5Al(Si 3Al)O 10(OH) 8Anthony et al , Handbook of mineralogy (2001)