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Wentworth scale identification and geology

A standardized classification system for sedimentary particles based on grain diameter, established by Chester K. Wentworth in 1922. The scale uses a geometric progression each size class is twice the previous and divides particles into: clay <0.004 mm , silt 0.004–0.0625 mm , sand 0.0625–2 mm , granule 2–4 mm , pebble 4–64 mm , cobble 64–256 mm , and boulder 256 mm . It is the standard grain-size nomenclature used in sedimentary geology. Field: sedimentology. Example: Using the Wentworth scale, a sedimentologist would describe a beach with particles averaging 0.5 mm in diameter as medium sand, while gravel bars with 10-cm clasts would be classified as small cobbles.. Related terms: Grain size, Sorting, Clast, Phi scale.

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Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner
GeoMiner
Last updated
2026-03-30T15:19:42.127987+00:00
Review status
Published; not independently peer-reviewed
  • USGS Thesaurus — U.S. Geological Survey. Controlled earth-science terminology used to describe USGS information resources.
  • Glossary of Geologic Terms — U.S. National Park Service. Geologic definitions prepared by the NPS Geologic Resources Inventory.

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Common questions

What does Wentworth scale mean in geology?
A standardized classification system for sedimentary particles based on grain diameter, established by Chester K. Wentworth in 1922. The scale uses a geometric progression each size class is twice the previous and divides particles into: clay <0.004 mm , silt 0.004–0.0625 mm , sand 0.0625–2 mm , granule 2–4 mm , pebble 4–64 mm , cobble 64–256 mm , and boulder 256 mm . It is the standard grain-size nomenclature used in sedimentary geology.
What is an example of Wentworth scale?
Using the Wentworth scale, a sedimentologist would describe a beach with particles averaging 0.5 mm in diameter as medium sand, while gravel bars with 10-cm clasts would be classified as small cobbles.
Which earth-science field uses the term Wentworth scale?
Wentworth scale is used in sedimentology.
Which terms are related to Wentworth scale?
Related terms in this reference are Grain size, Sorting, Clast, Phi scale.

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