Cronstedtite
From Wikipedia, the free encyclopedia
Cronstedtite is a complex iron silicate mineral belonging to the serpentine group of minerals. It has a formula of Fe2+2Fe3+(Si,Fe3+O5)(OH)4.
It was discovered in 1821 and named in honor of Swedish mineralogist Axel Fredrik Cronstedt (1722-1765). It has been found in Bohemia in the Czech Republic and in Cornwall, England.