Sandstone: Calcitic sedimentary stone, made up primarily from fragments of detritus and mineral granules, having dimensions between 1/6mm and 2mm. There are a great number of types of Sandstone depending on the genesis, structure and composition: eolianite, arkose (feldspathic-quartz sandstones) and lithic arenites (which may also be calcareous containing calcite or aragonite), etc.