A pisolite is a
sedimentary rock made of pisoids, which are concretionary grains – typically of
calcium carbonate which resemble
ooids, but are more than 2 mm in diameter.
Mindat - Pisolite
/ref> These grains are approximately spherical and have concentric layers reaching 10 mm in diameter.
The name derives from the Hellenic word for pea. Bauxites, limonite
Limonite () is an iron ore consisting of a mixture of hydrated iron(III) oxide-hydroxides in varying composition. The generic formula is frequently written as FeO(OH)·H2O, although this is not entirely accurate as the ratio of oxide to hydroxid ...
s, and siderites often have a pisolitic structure.
See also
* Ooid
* Oolite
Oolite or oölite (''egg stone'') is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Ancient Greek word for egg (ᾠόν). Strictly, oolites consist of ooids of diameter 0.25–2 ...
References
Further reading
*
Sedimentary rocks
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