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
Serpentine soil tolerant of extreme soil conditions, including: Physically these areas are characteristically steep, rocky, and vulnerable to erosion, which results in shallow soils. The shallow soils and sparse vegetation lead to elevated soil temperatures and dry conditions. Serpentine is a unique classification of soils as they are relatively rare, and exhibit distinct chemical properties. The soil in appearance is often reddish, brown, or gray in color. The parent material for serpentine soil is mostly derived from the rock serpentine, noted for its waxy greenish-silver to bluish-silver appearance. The rock has white streaks of mineral running through it that contain naturally occurring