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Download hereGENERAL DESCRIPTION
Rhodochrosite is a relatively rare manganese carbonate. Its beautiful pink-red colour is very appreciated by collectors. The crystals are transparent with translucent with a pearly luster. They are of pink to sharp red colour, the colouring being due to the presence of manganese in its composition (divalent manganese).
Rhodochrosite generally crystallizes in the form of rhombohedra, more rarely in scalenohedra, up to 12 cm. It deteriorates on its surface into a complex mixture of black manganese oxides, tarnishing its pink colour. Rhodochrosite is a species which is formed in the hydrothermal veins of a number of silver, lead, cupriferous and zincian ore bodies. It can be associated other manganese minerals such as rhodonite. It represents a minor source of manganese and can be used as hones decorative when it is stalactiform (as in Argentine) or massive. Rhodochrosite can also be cut (Colorado material) with facets and becomes a remarkable gem, although fragile.
The rhodochrosite deposits are rather numerous but few localities propose beautiful samples. The Emma mine in Colorado in USA where the pink crystals rhomboedric are in particular strewn with chalcopyrite. The famous Sweet Home mine (also in Colorado) gave splendid pink-purple to sharp red rhombohedra, of gem quality. Exceptional scalenohedra were discovered in the Wessel, Hotazel and Chwaning mines in the Cape Province in South Africa, like in Mounana in Gabon. One can also quote the recent discoveries in Peru (Uchucchacua mine in Oyon) and in China (mine Yaogangxian Mine in Yizhang, prefecture of Chenzhou, Hunan) and the "classical" deposit of Cavnic in Romania without forgetting Kassandra in Grèce.
In France, one finds rhodochrosite in many deposits in "Pyrenean manganese province" : Vieille-Aure, Nabias, Louron (Hautes-Pyrénées), Las Cabesses, Saint Girons (Ariège), Bagnères de Luchon (Haute-Garonne). Other occurrences exist in Brittany (near Guingamp), in Haute-Saône (Faucogney-Saphoz), in Hérault (Mas d'Alary).
The location of conservation of the type of this species is not known.
HISTORY : Name inspired from the Greek word "ρ-οδοσ" [rhodos] meaning "rose" and from "χρoσισ" [chrosis] meaning "colouring"
Espèce décrite en 1813 par Johann Friedrich Ludwig Hausmann (1782-1859), minéralogiste allemand
Type-locality : Kavnic (Kapnikbanya), Maramures, Roumania
CHEMICAL FORMULA : Mn2+ CO3
CRYSTAL SYSTEM : Rhomboedric
COLOR : Pink, red
DIAPHANIETY : Transparent to translucent
LUSTER : Vitreous, pearly
STREAK : White
MORPHOLOGIE : Prismatic crystals forming scalénohedras, stalactiform aggregates
HARDNESS : 3,5-4,0
CHEMICAL CLASS: 3,7
DENSITY : V - Carbonates, nitrates and borates
GROUP : Calcite
STRUNZ CLASS BEFORE 2001 : 5/B.02-50
STRUNZ CLASS AFTER 2001 : 5.AB.05
