Psephite is either a sediment

Sediment

Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

 or sedimentary rock

Sedimentary rock

Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....

 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

Rudite

Rudite is a general name used for a sedimentary rocks that are composed of rounded or angular detrital grains, i.e. granules, pebbles, cobbles, and boulders, which are coarser than sand in size. Rudites include sedimentary rocks composed of both siliciclastic, i.e. conglomerate and breccia, and...

. Shingle

Shingle beach

A shingle beach is a beach which is armoured with pebbles or small- to medium-sized cobbles. Typically, the stone composition may grade from characteristic sizes ranging from two to 200 mm diameter....

, gravel

Gravel

Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

, breccia

Breccia

Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....

, and especially conglomerate

Conglomerate (geology)

A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...

, would all be considered psephites. It is equivalent to the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

-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 Rudite Rudite is a general name used for a sedimentary rocks that are composed of rounded or angular detrital grains, i.e. granules, pebbles, cobbles, and boulders, which are coarser than sand in size. Rudites include sedimentary rocks composed of both siliciclastic, i.e. conglomerate and breccia, and...  (rudaceous)
Medium	sand(y)	psammite Psammite Psammite is a general term for sandstone. It is equivalent to the Latin-derived term arenite. Also, it is commonly used in various publications to describe a metamorphosed sedimentary rock with a dominantly sandstone protolith. In Europe, this term was formerly used for a fine-grained, fissile,...  (psammitic)	arenite Arenite Arenite is a sedimentary clastic rock with sand grain size between 0.0625 mm and 2 mm and contain less than 15% matrix. The related adjective is arenaceous...  (arenaceous)
Fine	clay(ey)	pelite Pelite Pelite is old and currently not widely used field terminology for a clayey fine-grained clastic sediment or sedimentary rock, i.e. mud or mudstone. It is equivalent to the Latin-derived term lutite. More commonly, metamorphic geologists currently use pelite for a metamorphosed fine-grained...  (pelitic)	lutite Lutite Lutite is old terminology, which is currently not widely used, by Earth scientists in field descriptions for fine-grained, sedimentary rocks, which are composed of silt-size sediment, clay-size sediment, or a mixture of both. When mixed with water lutites often disintegrate into mud... (lutaceous)