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
Poor on {110} and {100} very poor on {001}
Ca10(Mg,Fe)2Al4(SiO4)5(Si2O7)2(OH)4