Home > American Minerals V – October 1 > MS1673 Ramsdellite

Ramsdellite - Sold

Ramsdellite is simple manganese dioxide. Fleischer et al. (1962) named the mineral after Professor Lewis Stephen Ramsdell (1895-1975), mineralogist at the University of Michigan, who first distinguished the species from its polymorph pyrolusite. The discovery of ramsdellite at the Mistake mine dates to 1981 or so; an early account of the find appears in the Mineralogical Record's Arizona-V issue (1983).

Ramsdellite here forms brilliant disphenoidal crystals to 6 mm. The crystals form an interlocking and continuous coverage, built up as a mound on underlying gossan matrix. Nice example! This specimen was part of the Charles Trantham (1936-2020) estate. A Superstition Mineral & Mining Company label accompanies this specimen.