birnessite

== English == === Etymology === From Birness +‎ -ite, after Birness, Aberdeenshire, Scotland, where it was first described. === Noun === birnessite (plural birnessites) (mineralogy) A soft mineral, mostly containing manganese oxides, that occurs in manganese nodules. === Further reading === David Barthelmy (1997–2026), “Birnessite”, in Webmineral Mineralogy Database. “birnessite”, in Mindat.org, Keswick, Va.: Hudson Institute of Mineralogy, 2000–2026.