Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Subconchoidal, Conchoidal
Na 3(Na,K)Al 4Si 4O 16Ulrich Henn and Claudio C.
{100} Perfect, {110} Good, {011} Distinct
LiAl(PO 4)(OH,F)Walter Schumann , Gemstones of the world (2001) More from other references