The Collaborative International Dictionary
Psammite \Psam"mite\, n. [Gr. ? sandy, from ? sand: cf. F. psammite.] (Min.) A species of micaceous sandstone. -- Psam*mit"ic, a.
Wiktionary
n. (context mineralogy English) Any sandstone, but most often a metamorphosed rock unit with a dominantly sandstone protolith.
Wikipedia
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 termsTexture
Common
Greek
Latin
Coarse
gravel(ly)
psephite (psephitic)
rudite (rudaceous)
Medium
sand(y)
psammite (psammitic)
arenite (arenaceous)
Fine
clay(ey)
pelite (pelitic)
lutite (lutaceous)