Betzite [IMA 2021-037]
See the matrix in detail for a better differentiation in your collection
Na6Ca2(Al6Si6O24)Cl4 to cancrinite group
New IMA approved mineral betzite IMA 2021-037 see CNMNC Newsletter 62, Juni - Juli 2021..
With his alkali tectosilicate it’s dimorph to chemically identic quadridavyne (6/m). There is no possibility to make a macroscopic difference between betzite and often found quadridavyne or also davyne at Bellerberg volcano. Describing the origin piece found before by Bernd Ternes and analysed now for new identification as betzite you will find the typical matrix of associated quadridavyne with clear anorthite in board shape . The white matrix itself has carbonatic content so it’s linked in total with calcite, diopside pyroxene and small garnets of grossular and tobermorite.
Of course all collectors will check now there quadridavynes in the own collection if it’s the new betzite – but again, without an attached SXRD analyzation it’s a glance into a crystal ball.
IMA No. 2021-037
· Bellerberg paleovolcano, between Mayen and Kottenheim, Laacher See area, Eastern Eifel region, Rhineland-Palatinate, Germany
· Nikita V. Chukanov*, Natalia V. Zubkova, Olga N. Kazheva, Dmitry A. Varlamov, Igor V. Pekov, Dmitry I. Belakovskiy, Bernd Ternes, Willi Schüller, Sergey N. Britvin and Dmitry Y. Pushcharovsky
· Cancrinite group
· Hexagonal: P63; structure determined
· a = 12.8166(9), c = 5.3562(3) Å
· 11.14(31), 4.833(93), 3.715(95), 3.313(100), 2.787(37), 2.681(56), 2.474(35), 2.146(24)
· Type material is deposited in the collections of the Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18-2, Moscow 119071, Russia, registration number 5706/1
· How to cite: Chukanov, N.V., Zubkova, N.V., Kazheva, O.N., Varlamov, D.A., Pekov, I.V., Belakovskiy, D.I., Ternes, B., Schüller, W., Britvin, S.N. and Pushcharovsky, D.Y. (2021) Betzite, IMA 2021-037. CNMNC Newsletter 62; Mineralogical Magazine, 85, https://doi.org/10.1180/mgm.2021.62