The hardness of feldspar fluctuates between 6-6.5, the specific gravity fluctuates between 2-2.5, it is brittle, has high compressive strength, and has strong chemical stability to acid.

       The color of feldspar is mostly flesh red, but there are also gray and white brown. Sodium feldspar is white, gray, and light yellow, while calcium feldspar is white or light gray. Feldspar is an aluminosilicate mineral containing calcium, sodium, and potassium. There are many types of feldspar, such as albite, plagioclase, barite, plagioclase, orthoclase, and plagioclase. They all have a glassy luster and come in a variety of colors, including colorless, white, yellow, pink, green, gray, black, and so on. Some are transparent, some are semi transparent. Feldspar itself should be colorless and transparent. The reason why it is colored or not completely transparent is because it contains other impurities. Some form blocks, some form plates, some form columns or needles, and so on. Generally, the feldspar present in volcanic and metamorphic rocks is very small, only 0.1-10 millimeters. In porphyries, it can reach 5-10 centimeters, while in pegmatites, some can reach tens of meters. Feldspar is a raw material for the ceramic and glass industries.

      Potassium feldspar: K 2 O, Al 2 O 3.6 SiO 2, with K 2 O 9.55%, Al 2 O 3 above 16%, SiO 2 70%, density 2.56g/cm3, Mohs hardness 5.5, monoclinic crystal system, colors white, red, and milky white, melting point 1290 ° C.