{{short description|Sedimentary rock made of large grains, usually of calcium carbonate}} thumb|Pisoids in the Conococheague limestone (Upper Cambrian) of eastern Pennsylvania [[Image:Calcario2EZ.jpg|thumb|right|Pisolitic limestone; Itaboraí, Rio de Janeiro, Brazil; pisolith diameters average 1.0 cm]] [[Image:Qemscan_pisoliths.png|thumb|right|QEMSCAN mineral map of bauxite forming pisoids]]

A '''pisolite''' ({{ety|grc|''πίσον'' (píson)|pea}}) is a sedimentary rock made of '''pisoids''', which are concretionary grains – typically of calcium carbonate which resemble ooids, but are more than 2&nbsp;mm in diameter.<ref>[http://www.mindat.org/min-26778.html Mindat - Pisolite]</ref> These grains are approximately spherical and have concentric layers reaching 10&nbsp;mm in diameter.

Bauxites, limonites, and siderites often have a pisolitic structure.

==See also== * Ooid * Oolite

==References== {{Reflist}}

==Further reading== *{{cite book |last1=Manutchehr-Danai |first1=Mohsen |title=Dictionary of gems and gemology |date=2009 |publisher=Springer |isbn=978-3-540-72795-8 |edition=3rd}}

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Category:Sedimentary rocks

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