Grain size Grain size Grain size (or particle size) is the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. This is different from the crystallite size, which refers to the size of a single crystal inside a particle or grain. A single grain can be composed of several crystals. Granular material can range from very small colloidal particles, through clay, silt, sand, gravel, and cobbles, to boulders. Size ranges define limits of classes that are given names in the Wentworth scale (or Udden–Wentworth scale) used in the
Quartz arenite is known as a multicycle sand. Quartz arenite A quartz arenite or quartzarenite is a sandstone composed of greater than 90% detrital quartz, with limited amounts of other framework grains (feldspar, lithic fragments, etc.) and matrix. It can have higher-than-average amounts of resistant grains, like chert and minerals in the ZTR index. The term 'quartz arenite' is derived from the main component (quartz) and arenite, a Latin term for a rock with sand-sized grains. In some literature, these can be called orthoquartzites, a confusing term which usually refers to the metamorphic rock quartzite, though most metamorphic quartzites are diagentically fused