Sand 5 : A loose material must commonly composed of small quartz grains formed from the disintegration of preexisting rocks. Also see Sandstone. (ITOGP)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}