Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
{010} perfect; {100} good, interrupted; {101} indistinct; {001} in traces
NaBePO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Uneven, ConchoidalWalter Schumann
2,1 basal ; 2,1 prismatic ; 3,1 pinacoidal
Plagioclase Feldspar s: (Na,Ca)Al1-2Si3-2O8 Orthoclase Feldspar : KAlSi3O8