What is "psephite"

Psephite (, 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.

Pettijohn 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

Texture

Common

Greek

Latin

Coarse

gravel(ly)

psephite (psephitic)

rudite (rudaceous)

Medium

sand(y)

psammite (psammitic)

arenite (arenaceous)

Fine

clay(ey)

pelite (pelitic)

lutite (lutaceous)