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Rhodonite
Chemical Formula	(Mn2+,Fe2+,Mg,Ca)SiO3
Species	Silicates
Crystal System	Triclinic
Mohs Scale	5-6
Specific Gravity	3.57-3.76
Color	Rose-pink to brownish red, gray, or yellow
Streak	White
Luster	Vitreous, Pearly
Refractive Index	n = 1.711 - 1.738 n = 1.714 - 1.741 n = 1.724 - 1.751
Diaphaneity	Transparent, Translucent
Cleavage	PerfectPerfect on & Good on
Fracture	Irregular/Uneven, Conchoidal
Crystal Habit：Tabular crystals, massive, granular
Geological Setting：Manganese deposits formed by hydrothermal, contact or regional metamorphic, and sedimentary processes.

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 Greek ??δο? rhodos, rosy), often tending to brown because of surface oxidation.

Rhodonite crystals often have a thick tabular habit, but are rare. It has a perfect, prismatic cleavage, almost at right angles. The hardness is 5.5–6.5, and the specific gravity 3.4–3.7; luster is vitreous, being less frequently pearly on cleavage surfaces. The manganese is often partly replaced by iron, magnesium, calcium, and sometimes zinc which may sometimes be present in considerable amounts; a greyish-brown variety containing as much as 20% of calcium oxide is called bustamite; fowlerite is a zinciferous variety containing 7% of zinc oxide.

The inosilicate (chain silicate) structure of rhodonite has a repeat unit of five silica tetrahedra. The rare polymorph pyroxmangite, formed at different conditions of pressure and temperature, has the same chemical composition but a repeat unit of seven tetrahedra.

Rhodonite has also been worked as an ornamental stone. In the iron and manganese mines at Pajsberg near Filipstad and L?ngban in V?rmland, Sweden, small brilliant and translucent crystals (pajsbergite) and cleavage masses occur. Fowlerite occurs as large, rough crystals, somewhat resembling pink feldspar, with franklinite and zinc ores in granular limestone at Franklin Furnace in New Jersey.

Rhodonite is the official gem of Commonwealth of Massachusetts.