Sodium feldspar is generally gray - white, can also be colorless, can also have white, yellow, red, green or black; generally glassy crystals, specific gravity 2.605g/cm3, Mohs hardness of 6, sodium feldspar theoretical melting point of 1100 ° C, but the natural sodium feldspar ore, its melting point with the chemical composition of the different variations, brittle, fracture rougher.
