Skip to content
Mineralati

Minerals

Birnessite

birnessite

(Na,Ca,K)0.6(Mn⁴⁺,Mn³⁺)2O4·(H2O)1.5

Birnessite: Mineral information, data and localities.

Birnessite: Mineral information, data and localities. — via www.mindat.org · Source

Overview

Birnessite (nominally MnO2·nH2O), also known as δ-MnO2, is a hydrous manganese dioxide mineral with a chemical formula of Na0.7Ca0.3Mn7O14·2.8H2O. It is the main manganese mineral species at the Earth's surface, and commonly occurs as fine-grained, poorly crystallized aggregates in soils, sediments, grain and rock coatings (e.g., desert varnish), and marine ferromanganese nodules and crusts. It was discovered at Birness, Aberdeenshire, Scotland.

Identification characteristics

  • Mohs hardness 1.5

Scientific references

  1. Birnessite — Wikidata. https://www.wikidata.org/wiki/Q3640357 Link
  2. Birnessite — Wikipedia. https://en.wikipedia.org/wiki/Birnessite Link