a greenish micaceous mineral consisting essentially of a hydrous silicate of potassium, aluminum, and iron and occurring in greensand, clays, etc.
- glau·co·nit·ic [glaw-kuh-nit-ik], /ˌglɔ kəˈnɪt ɪk/, adjective
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How to use glauconite in a sentence
A greenish mineral called glauconite—a silicate of iron and alumina—is then formed.The Elements of Geology | William Harmon Norton
In a few places a red colour prevails, the iron being mostly oxidized; elsewhere the muds are green owing to abundant glauconite.
Red limestones usually contain haematite; in green limestones there may be glauconite or chlorite.
The sandstones are grey in colour, weathering buff or reddish-brown, tinged more or less green by grains of glauconite.The Geological Story of the Isle of Wight | J. Cecil Hughes
They are made of a mixture of sand and clay coloured dark green by a mineral called glauconite.The Geological Story of the Isle of Wight | J. Cecil Hughes
British Dictionary definitions for glauconite
a green mineral consisting of the hydrated silicate of iron, potassium, aluminium, and magnesium: found in greensand and other similar rocks. Formula: (K,Na,Ca) 0.5-1 (Fe,Al,Mg) 2 (Si,Al) 4 O 10 (OH) 2 .nH 2 O
- glauconitic (ˌɡlɔːkəˈnɪtɪk), adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012