Aug 15, 2019
Sandstone is a type of sedimentary rock that is mainly cemented by various sand grains with a particle diameter of 0.05-2mm, among which the sand content is greater than 50%, the structure is stable, usually light brown or red, and it mainly contains silicon, calcium, clay and oxidation iron. Most sandstones are composed of quartz or feldspar.
Mar 26, 2020
Mar 24, 2020
