Sandstones are sedimentary rocks usually composed of quartz cemented withsilica, iron oxideor calcium carbonate. Sandstones rangefrom very soft and friable to very hard and durable, depending on the depth at which it was buried and the nature of the cement. Generally, the most durable sandstones are cemented withsilica. Sandstone has a wide range of colors or textures. See quartz based stone. (Marble Institute, 2011)