Rhodochrosite is a

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

carbonate mineral Carbonate minerals are those minerals containing the carbonate ion, . Carbonate divisions Anhydrous carbonates *Calcite group: trigonal **Calcite CaCO3 **Gaspéite (Ni,Mg,Fe2+)CO3 **Magnesite MgCO3 **Otavite CdCO3 **Rhodochrosite MnCO3 **Sider ...

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 The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by t ...

varies between 3.5 and 4. Its

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water (molecule), wa ...

is between 3.5 and 3.7. It crystallizes in the trigonal system, and

cleaves Cleaves is a surname. Notable people with the surname include: * Henry B. Cleaves *Jessica Cleaves (1948–2014), American singer-songwriter *Margaret Cleaves (1848–1917), American physician *Mateen Cleaves (born 1977), American basketball player ...

with rhombohedral carbonate cleavage in three directions.

Crystal twinning Crystal twinning occurs when two or more adjacent crystals of the same mineral are oriented so that they share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals that are tightly ...

often is present. It is transparent to translucent with

refractive indices In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or ...

of ''nω''=1.814 to 1.816, ''nε''=1.596 to 1.598. It is often confused with the manganese silicate,

rhodonite Rhodonite is a manganese inosilicate, (Mn, Fe, Mg, Ca)SiO3 and member of the pyroxenoid group of minerals, crystallizing in the triclinic system. It commonly occurs as cleavable to compact masses with a rose-red color (the name comes from the G ...

, but is distinctly softer. It is officially listed as one of the

National symbols of Argentina Argentina has a number of national symbols, some of which are extensively defined by law. List of symbols References {{South America topic, National symbols of ...

. Rhodochrosite forms a complete

solid solution A solid solution, a term popularly used for metals, is a homogenous mixture of two different kinds of atoms in solid state and have a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The wor ...

series with

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

carbonate (

siderite Siderite is a mineral composed of iron(II) carbonate (FeCO3). It takes its name from the Greek word σίδηρος ''sideros,'' "iron". It is a valuable iron mineral, since it is 48% iron and contains no sulfur or phosphorus. Zinc, magnesium and ...

Calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...

, (as well as

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

and

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

, 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 discovery

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 Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. It was first described in 1813 in reference to a sample from Cavnic, Maramureş, present-day

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...

. 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 Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word ῥοδόχρως meaning ''rose-colored''.

Use

Its main use is as an ore of

, which is a key component of low-cost stainless steel formulations and certain

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

alloys. Quality banded specimens are often used for decorative stones and

jewelry Jewellery ( UK) or jewelry ( U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a w ...

. 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 Amalgamation is the process of combining or uniting multiple entities into one form. Amalgamation, amalgam, and other derivatives may refer to: Mathematics and science * Amalgam (chemistry), the combination of mercury with another metal **Pan am ...

process used in the concentration of

silver ore Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical cond ...

s, and were often discarded on the mine dump.

Culture

Rhodochrosite is Argentina's "national

gemstone A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, ...

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

officially named rhodochrosite as its state mineral in 2002. It is sometimes called "Rosa del Inca", "Inca Rose" or ''Rosinca''.

Gallery

File:The_Searchlight_Rhodochrosite_Crystal.jpg, "The Searchlight," Large red rhodochrosite from Sweet Home Mine,

Alma, Colorado Alma is a Statutory Town in Park County, Colorado, United States. The town population was 296 at the 2020 United States Census. Alma is located West and South of the Denver-Aurora-Lakewood, CO Metropolitan Statistical Area and the Front Range ...

File:Fluorite-Quartz-Rhodochrosite-ed10a.jpg, Rhodochrosite with fluorite, tetrahedrite and quartz File:Rhodochrosite_Pink_Form.jpg, Pink is the most common color of Rhodochrosite. Specimen mined near Silverton, Colorado File:Alma_King_rhodochrosite.jpg, The Alma King is the largest known rhodochrosite crystal; it was found in the Sweet Home Mine near Alma, Colorado. It is on display in the

Denver Museum of Nature and Science The Denver Museum of Nature & Science is a municipal natural history and science museum in Denver, Colorado. It is a resource for informal science education in the Rocky Mountain region. A variety of exhibitions, programs, and activities help mus ...

. File:Rodocrosita_2.jpg, Exhibit in

La Plata Museum The La Plata Museum ( es, Museo de la Plata) is a natural history museum in La Plata, Argentina. It is part of the (Natural Sciences School) of the UNLP ( National University of La Plata). The building, long, today houses 3 million fossils an ...

, La Plata,

File:The Alma Rose.jpg, The Alma Rose specimen from the Sweet Home Mine in Alma, CO. Located at the Rice Northwest Museum of Rocks and Minerals in Hillsboro, OR.

References

* Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., . {{National emblems of Argentina Carbonate minerals Manganese(II) minerals Symbols of Colorado Trigonal minerals Minerals in space group 167 National symbols of Argentina

Occurrence and discovery

Use

Culture

Gallery

See also

References