Name/Title
RhodoniteEntry/Object ID
2024.1.26Description
About Rhodonite
Formula: CaMn3Mn[Si5O15]Often contains minor Mg and Fe. Structural studies and the recognition of new species in the rhodonite group indicate that the former simplified MnSiO3 formula no longer represents the overall rhodonite group. A pure Mn-dominant rhodonite is better expressed as Mn2+Mn2+3Mn2+[Si5O15], and indeed in 2019 this composition was recognized as the new rhodonite-group end-member vittinkiite.
The five cation sites M1-M5 exhibit ordering, which has given rise to such species as ferrorhodonite, which requires M5 to be Ca-dominant and M4 to be Fe2+-dominant.
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, GermanyPolymorph of:Pyroxmangite, UM1975-18-SiO:Mn
Pyroxmangite of MnSiO3 composition is the high-pressure, low-temperature polymorph with respect to rhodonite of the same composition (Maresch & Mottana, 1976). There is also an unnamed α phase - UM1975-18-SiO:Mn - recognized in limestones from the Polish Tatra Mountains.
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.Collection
John Morrow CollectionLocation
Location
Display Case
FS-11Room
Frieda Smith HallBuilding
Crater Rock MuseumCategory
ExhibitMoved By
Ian C.Date
January 29, 2025Notes
Inventory/ locationLocation
Shelf
CS-F-1Room
Curation StorageBuilding
Crater Rock MuseumCategory
StorageMoved By
CuratorDate
February 21, 2024