Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
[100] perfect [010] imperfect with 79° angle between
Uneven, ConchoidalWalter Schumann
2,1 basal ; 2,1 prismatic ; 3,1 pinacoidal
Plagioclase Feldspar s: (Na,Ca)Al1-2Si3-2O8 Orthoclase Feldspar : KAlSi3O8