Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
{100} Perfect, {010} Distinct, {102} Distinct
Zn 2(Fe2+ ,Mn2+ )(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Perfect on {001}, imperfect on {110}
(K,Na)Ca4Si8O20(F,OH)•8(H2O)