Rhodonite
Formula: CaMn3Mn[Si5O15]
Species: Silicates – (Innosilicates)
Colour: Red, pink, brownish-red, gray.
Lustre: Vitreous, Pearly
Hardness: 5½ – 6½
Specific Gravity: 3.57 – 3.76
Crystal System: Triclinic
Member of: Rhodonite Group
Name: Named in 1819 by Christoph Friedrich Jasche from the Greek ρόδον, “rose”, referring to its color.
Type Locality: Kaiser Franz Mine (König Wilhelm Mine), Schävenholz, Elbingerode, Oberharz am Brocken, Harz, Saxony-Anhalt – Germany
Polymorph of: Pyroxmangite, Pyroxmangite of MnSiO3 composition is the high-pressure, low-temperature polymorph with respect to rhodonite of the same composition. The Fe-substituted analogue is known – see ferrorhodonite. Some preliminary analyses indicate much material currently called rhodonite is actually vittinkiite, ferrorhodonite or pyroxmangite, and probably should be termed rhodonite group until analysed. Most of these species are slightly darker than true rhodonite but chemical analysis and sometimes XRD is required for identification.