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
Silt, Colorado west. U.S. Route 6 is Main Street in Silt, and provides a local route parallel to I-70. According to the United States Census Bureau, the town has a total area of , of which , or 1.46%, is water. This climatic region is typified by large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold) winters. According to the Köppen Climate Classification system, Silt has a humid continental climate, abbreviated "Dfb" on climate maps. As of the census of 2000, there were 1,740 people, 648 households, and 452 families residing in the town.