Nontronite is the iron(III) rich member of the smectite group of clay minerals. Nontronites typically have a chemical composition consisting of more than ~30% Fe2O3 and less than ~12% Al2O3 (ignited basis). Nontronite has very few economic deposits like montmorillonite. Like montmorillonite, nontronite can have variable amounts of adsorbed water associated with the interlayer surfaces and the exchangeable cations.
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Nontronite is the iron(III) rich member of the smectite group of clay minerals. Nontronites typically have a chemical composition consisting of more than ~30% Fe2O3 and less than ~12% Al2O3 (ignited basis). Nontronite has very few economic deposits like montmorillonite. Like montmorillonite, nontronite can have variable amounts of adsorbed water associated with the interlayer surfaces and the exchangeable cations.
Ignoring the isomorphic substitution of Si by Al, with exchangeable cations compensating for the resulting negative electrical charges and their hydration water in the interlayers, the elemental composition of nontronite could be idealised as simply {{Chem2|Fe^{III}2Si4O10(OH)2}}.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).