Definition of piemontite in English:



mass noun
  • A brown or black mineral consisting of a silicate of calcium, aluminium, iron, and manganese.

    • ‘Since the formation of piemontite is dependant of a high concentration of manganese it is commonly found together with other manganese minerals.’
    • ‘The limit of piemontite solid solubility is found near p=1.9 at the above conditions.’
    • ‘Piemontite has beautiful, high-order interference colors.’
    • ‘He reported that material previously said to be piemontite was actually a manganan epidote.’
    • ‘It forms a series with clinozoisite and, together with a group of other minerals including zoisite, the allanites, and piemontite, is a dominant member of the epidote group.’


Late 19th century: from Italian Piemonte (see Piedmont) + -ite.