1 Physical Properties
1.1 Tenacity
Very brittle
Not Available
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Conchoidal, Brittle, Conchoidal
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
1.6 Cleavage
{010} perfect, {110} distinct, {100} in traces
None
1.7 Mohs Hardness
1.8 Chemical Composition
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references
NaFe3+3Fe3+6(BO 3) 3Si 6O 18(O,OH) 4Anthony et al , Handbook of Mineralogy (2001)