Psephite (Greek: psephos, pebble) is either a sediment or sedimentary rock composed of fragments that are coarser than sand and which are enclosed in a matrix that varies in kind and amount. It is equivalent to a rudite. Shingle, gravel, breccia, and especially conglomerate, would all be considered psephites. It is equivalent to the Latin-derived term rudite. Psephite is more commonly used for a metamorphosed rudite.[1]

Pettijohn [2] gives the following descriptive terms based on grain size, avoiding the use of terms such as "clay" or "argillaceous" which carry an implication of chemical composition:

Descriptive size terms
Coarsegravel(ly)psephite (psephitic)rudite (rudaceous)
Mediumsand(y)psammite (psammitic)arenite (arenaceous)
Fineclay(ey)pelite (pelitic)lutite (lutaceous)
  • references


  1. ^ Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, J.A., eds. (2005) Glossary of Geology (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. ISBN 0-922152-76-4
  2. ^ Pettijohn F. J. (1975), Sedimentary Rocks, Harper & Row, ISBN 0-06-045191-2
Other Languages
Deutsch: Psephit
Esperanto: Psefito
ქართული: ფსეფიტი
Кыргызча: Псефит
Nederlands: Psefiet
polski: Psefity
русский: Псефит
українська: Псефіти
Tiếng Việt: Psephit