A sedimentary rock which mainly constitutes of sand-sized minerals or grains is known as a sandstone rock. Most of the sandstone are made of or composed of quartz and/or feldspar as they are the most common minerals found in the crust of the earth. Sandstone is made up of cemented grains which maybe fragments of pre-existing rocks or mono-minerallic crystals. They are bound together by clays, calcite and silica. They are also composed of siltstones and shale, and they also include larger grains such as breccias and conglomerates.

There are two stages to the formation of sandstone. First is either from sedimentation from water or from air and the sedimentation by sand. There are three types of sandstones:-
1. Argillaceous sandstones
2. Arkosic sandstones
3. Quartzose sandstones