Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Poor/indistinct on {1120} and {1011}
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) More from other references
Perfect on {001}, imperfect on {110}
(K,Na)Ca4Si8O20(F,OH)•8(H2O)