Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Conchoidal, Uneven, Conchoidal to uneven
[0001] indistinct, [1010] indistinct
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references
Na 2(Ti,Fe)Si 4(O,F) 11Ulrich Henn and Claudio C.