Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Distinct on [010] and [100] poor on [101]
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)
Uneven, ConchoidalWalter Schumann
2,1 basal ; 2,1 prismatic ; 3,1 pinacoidal
Plagioclase Feldspar s: (Na,Ca)Al1-2Si3-2O8 Orthoclase Feldspar : KAlSi3O8