Sandstone is categorised as a sedimentary rock. Formed from sediment that consists of mineral clasts and rock fragments. Additionally, it is predominantly composed of medium-sized sand particles. Classifying it as a medium-grained clastic sedimentary rock. Specifically, the sand grains in sandstone range from 1/16 millimeter to 2 millimeters in size. Therefore, with silt being finer and gravel being coarser. These sand grains, also known as framework grains, are the primary components of sandstone.
 
While sandstone may contain varying proportions of finer and coarser materials. It retains its classification as sandstone. However, if it comprises more than 30 percent of gravel, cobble, or also boulder-sized grains. It is instead classified as conglomerate or breccia. Collectively referred to as rudites. Apart from sediment particles, sandstone also contains two other essential components: matrix and cement. Matrix refers to the fine-grained material, such as silt and clay. That was present in the sediment alongside the sand. In contrast, cement is the mineral matter introduced at a later stage, binding the sediment together to form rock.