Sandstone is actually a sedimentary rock formed by the consolidation and compaction of sand, which is held together by a natural cement, such as silica. Sandstone is typically the youngest of the quartz-based stones, with each stone having a different level of porosity, hardness and compressive strength. Owing to their natural beauty, sandstones are used for interior as well as exterior decoration including flooring, paving, cladding walls and floors.