2019-12-24 · Sandstone is a classic sedimentary rock comprising an aggregate of sandsized (0.06–2.0mm) fragments of minerals, rocks or fossils held together by a mineral cement. Actually, sandstone forms when sand is buried under successive layers of sediment. During burial the sand is compacted and a binding agent such as quartz, calcite or iron oxide is precipitated from ground water which moves through passageways between grains to create Sandstone.