Psammite

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This article is about a type of sedimentary rock. For the work by Archimedes, Psammites, see The Sand Reckoner.

Psammite (Greek Psammos, Sand) is a general term for a sandstone, most often used to describe a metamorphosed rock unit with a dominantly sandstone protolith. An alternative term, more commonly used for unmetamorphosed sediments, is arenite (adj arenaceous). Pettijohn ^[1] 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)

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