What is "psammite"

Psammite \Psam"mite\, n. [Gr. ? sandy, from ? sand: cf. F. psammite.] (Min.) A species of micaceous sandstone. -- Psam*mit"ic, a.

n. (context mineralogy English) Any sandstone, but most often a metamorphosed rock unit with a dominantly sandstone protolith.

Psammite ( Greek psammos, sand) 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, clayey sandstone. 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)