Formula: MnCO3 Hexagonal
Description: Rhodochrosite is an attractive pink mineral formed generally by hydrothermal processes associated with igneous activity or the metamorphism of manganese-rich rocks.
IRON COUNTY: Rhodochrosite was found at the Montreal Mine as crystals, druses and massive cleavable material associated with barite, quartz, manganiferous calcite, manganite, barite and talc. Large well-crystallized specimens of these minerals were found in vugs in the iron formation during the heydays of mining. These specimens are now available only from dealers and are highly sought after by collectors. One of the more unique habits of rhodochrosite, as described by Dickey (1938), is as “arborescent aggregaters of small tabular rhombohedral pink crystals which resemble flos ferri”.
MARATHON COUNTY: Thin pale pink crusts of rhodochrosite were found on rhyolite in the 3M quarry near Wausau, as represented on specimens stored in the Milwaukee County Museum.