pyrochroite
/ˌpʌɪrə(ʊ)ˈkrəʊʌɪt/Mineralogy
noun
A manganese-containing mineral which occurs in hydrothermal vein deposits, often as pale greenish or bluish crystals in foliated masses which darken on exposure.
- Pyrochroite is manganese (ii) hydroxide, Mn(OH)2; the manganese analogue of brucite. Crystal system: trigonal..
Origin
Mid 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. From German Pyrochroit from pyro- + ancient Greek χροιά colour + German -it, so called because it becomes coloured when heated.