Fluoro-richterite

(repeating unit)Na(NaCa)Mg5Si8O22F2IMA symbolFlrct[1]Strunz classification9.DE.20Crystal systemMonoclinicCrystal classPrismatic (2/m)
(same H-M symbol)Space groupC2/mUnit cella = 9.763, b = 17.89
c = 5.122 [Å]; β = 102.25°; Z = 2IdentificationColorBrown to brownish-red, rose-red, yellow, grey-brown, also pale to dark greenMohs scale hardness5–6LusterVitreousStreakWhiteSpecific gravity3.17References[2][3][4]

Fluororichterite is a rare amphibole with formula Na(NaCa)Mg5Si8O22F2.

Occurrence

Fluororichterite was first reported from the Ilmen Nature Reserve, Ilmen Mountains, Chelyabinsk Oblast', Southern Urals, Russia. It was recognized by the International Mineralogical Association in 1994. Its name is derived from its fluorine content and relation to richterite.[2]

At the type locality in the Ilmen Mountains fluororichterite occurs in carbonate veins in amphibolites and ultramafic rocks.[5] In the Essonville occurrence in Wilberforce, Ontario it occurs in a limestone lens within a gneiss and is associated with phlogopite and calcite.[6] It has also been reported from Austria, Germany, Italy, Spain and China.[2] At Coyote Peak in the Coastal Range, Humboldt County, California, it occurs with a variety of rare minerals in an alkaline mafic diatreme.[7]

References

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b c Fluororichterite: Mindat.org
  3. ^ Fluororichterite: Webmineral.com
  4. ^ "IMA Master List". Archived from the original on 2015-01-05. Retrieved 2014-05-12.
  5. ^ Type locality, Ilmen Mtns
  6. ^ Essonville location, Mindat
  7. ^ Coyote Peak, Mindat