RHODOCHROSITE
Rhodochrosite is a manganese carbonate (MnCO3).
Most rhodochrosite is pinkish, but high-quality specimens are a gorgeous red
color. Its crystals are rhomb-shaped. It has a glassy, nonmetallic
luster, a white streak, and has a hardness of about 3.5 to 4.
Rhodochrosite (pink) (field of view ~5.9 cm across)
Rhodochrosite (deep red) (Early Oligocene, 30-31 m.y.) from the Sweet Home Mine near
Alma, Colorado, USA. (CMNH 24223, Cleveland Museum of Natural History
public display, Cleveland, Ohio, USA.
Rhodochrosite (red), bertrandite (whitish-peach) + other minerals on an attractive
plate from the Kounrad Massif, Kazakhstan. (public display, Carnegie
Museum of Natural History, Pittsburgh, Pennsylvania, USA)
Rhodochrosite (Early Oligocene, 30-31 m.y.) from the Sweet Home Mine near Alma,
Colorado, USA. (Cranbrook Institute of Science specimen, Bloomfield
Hills, Michigan, USA)
Rhodochrosite (red) & tetrahedrite (silvery-gray, Cu12Sb4S13)
(Early Oligocene, 30-31 m.y.) from the Sweet Home Mine near Alma, Colorado, USA
(CSM # SH3407, Colorado School of Mines Geology Museum, Golden, Colorado, USA).
Rhodochrosite from the Eagle Mine near Gilman, Eagle County, central Colorado, USA
(CSM # 82.61, Colorado School of Mines Geology Museum, Golden, Colorado, USA).
Rhodochrosite from the Climax Mine, Climax Mining District, Lake County, Colorado,
USA (CSM # 81.96, Colorado School of Mines Geology Museum, Golden, Colorado,
USA).
Rhodochrosite (red) & quartz (clearish-gray) & tetrahedrite (silvery-gray,
Cu12Sb4S13) (Early Oligocene, 30-31 m.y.) from
the Sweet Home Mine's Strawberry Pocket, Fluorite Raise, near Alma, Colorado,
USA (Colorado School of Mines Geology Museum public display, Golden, Colorado,
USA).
Rhodochrosite (red) & tetrahedrite (silvery-gray, Cu12Sb4S13)
(Early Oligocene, 30-31 m.y.) from the Sweet Home Mine's Pincushion Pocket,
Fluorite Raise, near Alma, Colorado, USA.
Rhodochrosite from Guangxi Province, South China. (Hillman Hall of Minerals
and Gems specimen, Carnegie Museum of Natural History, Pittsburgh,
Pennsylvania, USA)
Mammiform (botryoidal) rhodochrosite from the Oppu Mine, Aomori Prefecture, northern
Honshu Island, Japan. The Oppu Mine exploited a polymetallic sulfide vein
deposit in the Oppu Formation (Nishikurosawa Stage, lower Middle Miocene), a
succession of intermediate to felsic, submarine, effusive to explosive
volcanics. The principal ore minerals are sphalerite, galena, and chalcopyrite.
Other sulfide minerals present are pyrite and pyrrhotite. Principal
gangue minerals are quartz, calcite, and rhodochrosite (see above).
Mining targets were lead (from galena), zinc (from sphalerite), copper (from
chalcopyrite), and silver (Ag) & cadmium (Cd) impurities in the sulfide
minerals. Specimen owned by John Rakovan. (Some info. from Hattori
& Sakai, 1979, D/H ratios, origins, and evolution of the ore-forming fluids
of the Neogene veins and Kuroko deposits of Japan, Economic Geology 74:
535-555.)
Botryoidal rhodochrosite (8.8 cm across at its widest) from an unrecorded
locality (South America?). Specimen owned by Clarence Santos.
Photo gallery of
rhodochrosite