Rhodonite

rhodonite

Rhodonite from Pajsberg, Swed.

(credit: Courtesy of the Field Museum of Natural History, Chicago; photograph, John H. Gerard)

Silicate mineral that occurs in various manganese ores, often with rhodochrosite. A manganese silicate, MnSiO₃, with small amounts of iron and calcium, it is found in the Ural Mountains, Sweden, Australia, California, New Jersey, and elsewhere. Rhodonite is the primary source of some important manganese oxide deposits, such as the manganese ores of India. Fine-grained rhodonite of clean, pink colour is a desirable gem and ornamental stone.

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rhodonite [′rōd·ən‚īt]

(mineralogy)

MnSiO₃A pink or brown mineral inosilicate crystallizing in the triclinic system and commonly found in cleavable to compact masses or in embedded grains; luster is vitreous, hardness is 5.5-6 on Mohs scale, and specific gravity is 3.4-3.7.

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Rhodonite 

a mineral of the silicate class with the chemical formula CaMn₄[Si₅O₁₅]. Natural rhodonites contain 30–46 percent MnO, 4-6.5 percent CaO, and 45-48 percent SiO₂, with admixtures of FeO (up to 12 percent), Zn (fowlerite), Mg, and Al. Rhodonite crystallizes in the triclinic system. The structure of the crystal lattice is represented by complex chains of two repeating diorthogroups of Si₂O₇ connected by SiO₄ tetrahedrons, between which MnO₆ and CaO₆ octahedrons are distributed. Tabular and prismatic crystals are rarely found; granular and dense masses are usual. The mineral is rose-red and has a vitreous luster. It has a hardness of 5.5-6 on Mohs’ scale and a density of 3,400-3,750 kg/m³.

Rhodonite is a low-temperature mineral in hydrothermal and contact-metamorphic formations that are rich in manganese oxides and is associated with bustamite, rhodochrosite, tephroite, and manganese garnet. It is used as a face and ornamental stone. In the USSR, rhodonite deposits are found near Sverdlovsk in the Urals, where the mineral is called orlets. Other deposits are at Långban, Sweden; Conningham, Mass., USA; and Xonotla, Mexico.