.

Rhodonite Mineral Facts:

Chemical Formula: MnSiO₃ - Manganese Carbonate

Colors: Usually shades pink to rose red.

Hardness: 6 to 6.5

Density: 3.6

Cleavage: Two Perfect prismatic cleavages. Although crystals are fairly common in some places, the mineral is more usually found in dense,  finely granular masses.

Crystallography: Hexagonal

Luster:. Vitreous, transparent to opaque - usually translucent to opaque.

Optics: (Refractive Index)  = 1.73
 

Composition, Structure and Associated Minerals:
Occurs as a veinstone in lead and silver-lead veins (as at Broken Hill, N.S.W.), associated with rhodochrosite and quartz. Rhodonite occurs in veins of magnetite, copper and other metals, and in contact zones between limestones, shales and igneous rocks, associated with other manganese minerals. Under these conditions they may have been concentrated by the help of magmatic separations. Rhodonite also occurs also with rhodochrosite in deposits of manganese ores and in other associations, where it may be of secondary origin - formed from the alteration of manganese bearing ores.

When exposed to the effects of weather, rhodonite will alter to a mixture of which the principal constituents are a manganese oxide, MnO₂, silica and water, or to mixtures of carbonates of manganese, or a mixture of the carbonates of manganese, iron and calcium.

Identification and Diagnostics
Rhodonite is distinguished from rhodochrosite by its greater hardness and the fact that it is insoluble in hydrochloric acid.

Occurrence, Localities and Origins:
Rhodonite is found in large masses near Ekaterinburg, Urals; and at Broken Hill, New South Wales. Crystals of rhodonite and bustamite occur in iron ore deposits in the gneiss of Langban, Sweden. Fine crystals of rhodonite are found in the iron ore at Pajsberg, Sweden, and crystals of fowlerite in metamorphosed limestone associated with the zinc ores at Stirling Hill and Franklin Furnace, N. J. Massive rhodonite is abundant at Jekaterinburg, Ural, Russia; at Kapnik, Hungary; at Blue Hill Bay, Maine; and in Jackson Co., N. C., associated with wad.

Transparent rhodonite is used as a gemstone to a limited extent. The principal occurrences of gem rhodonite in the US are in Siskiyou Co., Cal., and near Butte, Mont. In the former locality the mineral occurs nine miles north of Happy Camp in a fine-grained quartz schist. It consists of a mixture of quartz grains cemented by rhodonite and traversed by veins of pyrolusite. The Montana material is in radiating groups with quartz, pyrite and brown manganese oxide. At the Alice Mine it is associated with rhodochrosite.

.Return to the Mineral Collectors Information Page

Nevada Outback Gems