Wentworth Grain Size Scale
Wentworth grain size chart modified to include particle diameters in inches and phi units as well as standard sieve sizes and other useful parameters. Diagram is from Williams, S.J., Arsenault, M.A., Buczkowski, B.J., Reid, J.A., Flocks, J.G., Kulp, M.A., Penland, S., and Jenkins, C.J., 2006, Surficial sediment character of the Louisiana offshore Continental Shelf region: a GIS Compilation, U.S. Geological Survey Open-File Report 2006-1195, online at http://pubs.usgs.gov/of/2006/1195/index.htm and content is in the public domain .