1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.33-2.373.30-3.40
1
7.18
1.5 Fracture
Uneven, Brittle, Uneven, Brittle, Uneven
Conchoidal, Brittle, Conchoidal
1.6 Cleavage
Perfect on {001}, imperfect on {110}
{010} perfect, {110} distinct, {100} in traces
1.7 Mohs Hardness
1.8 Chemical Composition
(K,Na)Ca4Si8O20(F,OH)•8(H2O)
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references