Crystal chemistry and nomenclature of rhodonite-group minerals. (9th December 2019)

• Record Type: Journal Article
• Authors: Shchipalkina, Nadezhda V.; Pekov, Igor V.; Chukanov, Nikita V.; Biagioni, Cristian; Pasero, Marco
• Is Part Of: Mineralogical magazine. Volume 83:Number 6(2019)
• Page Start: 829
• Page End: 835
• Publication Date: 2019-12-09
• Subjects: rhodonite, -- ferrorhodonite, -- vittinkiite, -- rhodonite group, -- manganese silicate, -- inosilicate, -- pyroxenoid, -- mineral nomenclature; Mineralogy -- Periodicals; Mineralogy -- Great Britain -- Periodicals; 549.05
• DOI: 10.1180/mgm.2019.65
• Languages: English
• ISSNs: 0026-461X

Abstract

Abstract: This paper presents the nomenclature of the rhodonite group accepted by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA). An overview of the previous studies of triclinic (space group P $\bar{1}$ ) pyroxenoids belonging to the rhodonite structure type, with a focus on their crystal chemistry, is given. These minerals have the general structural formula VII M (5) VI M (1) VI M (2) VI M (3) VI M (4)[Si5 O15 ]. The following dominant cations at the M sites are known at present: M (5) = Ca or Mn 2+, M (1–3) = Mn 2+ ; and M (4) = Mn 2+ or Fe 2+ . In accordance with the nomenclature, the rhodonite group consists of three IMA-approved mineral species having the following the general chemical formulae: M (5) A M (1–3) B3 M (4) C[Si5 O15 ], where A = Ca or Mn 2+ ; B = Mn 2+ ; and C = Mn 2+ or Fe 2+ . The end-member formulae of approved rhodonite-group minerals are as follows: rhodonite CaMn3 Mn[Si5 O15 ]; ferrorhodonite CaMn3 Fe[Si5 O15 ]; and vittinkiite MnMn3 Mn[Si5 O15 ].