Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It streaks white, and its Mohs hardness varies between 3.5 and 4. Its specific gravity is between 3.5 and 3.7. It crystallizes in the trigonal system, and cleaves with rhombohedral carbonate cleavage in three directions. Crystal twinning often is present. It is transparent to translucent with refractive indices of =1.814 to 1.816, =1.596 to 1.598. It is often confused with the manganese silicate, rhodonite, but is distinctly softer. It is officially listed as one of the National symbols of Argentina.

Rhodochrosite on Matrix - Peru.jpg
CategoryCarbonate minerals
(repeating unit)
IMA symbolRds[1]
Strunz classification5.AB.05
Crystal systemTrigonal
Crystal classHexagonal scalenohedral (3m)
H-M symbol: (3 2/m)
Space groupR3c
Unit cella = 4.777, c = 15.67 [Å]; Z = 6
Formula mass114.95 g/mol
ColorPink, rose, rose-red, red, cherry-red, yellow, yellowish gray, gray, cinnamon-brown, white, may be banded; colourless to pale rose in transmitted light.
Crystal habitRhombohedral and scalenohedral crystals; also commonly bladed, columnar, stalactitic, botryoidal, granular or massive
TwinningOn {1012} as contact and lamellar
CleavageOn {1011} perfect; parting on {1012}
FractureUneven, conchoidal
Mohs scale hardness3.5–4
LusterVitreous to pearly
DiaphaneityTransparent to translucent
Specific gravity3.7
Optical propertiesUniaxial (-)
Refractive indexnω = 1.814–1.816 nε = 1.596–1.598
Birefringenceδ = 0.218
Ultraviolet fluorescenceNone

Rhodochrosite forms a complete solid solution series with iron carbonate (siderite). Calcium, (as well as magnesium and zinc, to a limited extent) frequently substitutes for manganese in the structure, leading to lighter shades of red and pink, depending on the degree of substitution. It is for this reason that the most common color encountered is pink.

Occurrence and discoveryEdit

Rhodochrosite occurs as a hydrothermal vein mineral along with other manganese minerals in low temperature ore deposits as in the silver mines of Romania where it was first found. Banded rhodochrosite is mined in Capillitas, Argentina.

It was first described in 1813 in reference to a sample from Cavnic, Maramureş, present-day Romania. According to Dimitrescu and Radulescu, 1966 and to Papp, 1997, this mineral was described for the first time in Sacaramb, Romania, not in Cavnic, Romania. The name is derived from the Greek word ῥοδόχρως meaning rose-colored[citation needed].


Its main use is as an ore of manganese, which is a key component of low-cost stainless steel formulations and certain aluminium alloys. Quality banded specimens are often used for decorative stones and jewelry. Due to its being relatively soft, and having perfect cleavage, it is very difficult to cut, and therefore rarely found faceted in jewelry.

Manganese carbonate is extremely destructive to the amalgamation process used in the concentration of silver ores, and were often discarded on the mine dump.


Stereo image
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Small Rhodochrosite specimen featured in a mineral kit, from Wuton mine, Guangxi prov, China.

Rhodochrosite is Argentina's "national gemstone".[5][6] Colorado officially named rhodochrosite as its state mineral in 2002.[7]

It is sometimes called "Rosa del Inca", "Inca Rose" or Rosinca.[8]


See alsoEdit


  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Handbook of Mineralogy
  3. ^ Rhodochrosite data on Mindat
  4. ^ Rhodochrosite data on Webmineral
  5. ^ "Piedra nacional: la Rodocrosita" (in Spanish). Embassy of the Argentine Republic in the Colombian Republic. Retrieved 7 October 2013.
  6. ^ Moreno, María (9 November 2002). "La piedra argentina". Página/12 (in Spanish). Retrieved 7 October 2013.
  7. ^ "Colorado State Archives; Symbols & Emblems". Retrieved 2 February 2012.
  8. ^ R. V. Dietrich (2005-07-16). "Rhodochrosite". Retrieved 2007-08-15.
  • Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0-471-80580-7.