Zincoberaunite, ZnFe3+ 5(PO4)4(OH)5⋅6H2O, a new mineral from the Hagendorf South pegmatite, Germany

Nikita V. Chukanov, Igor V. Pekov, Ian E. Grey, Jason R. Price, Sergey N. Britvin, Maria G. Krzhizhanovskaya, Anthony R. Kampf, Bernhard Dünkel, Erich Keck, Dmitry I. Belakovskiy, Colin M. MacRae

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

The new mineral zincoberaunite, ideally ZnFe3+ 5(PO4)4(OH)5·6H2O, the Zn analogue of beraunite, is found in the Hagendorf South granitic pegmatite, Hagendorf, Bavaria, Germany, in two associations: (1) with potassium feldspar, quartz, jungite, phosphophyllite and mitridatite (the holotype) and (2) with flurlite, plimerite, Zn-bearing beraunite, schoonerite, parascholzite/scholzite, robertsite and altered phosphophyllite (the cotype). Zincoberaunite occurs as radial or randomly oriented aggregates of flexible fibers up to 1.5 mm long and up to 3 μm thick. Dcalc is 2.92 g/cm3 for the holotype and 2.94 g/cm3 for the cotype. Zincoberaunite is optically biaxial (–), α = 1.745(5), β = 1.760(5), γ = 1.770(5), 2Vmeas = 80(5)°. Chemical composition of the holotype (electron probe microanalyser; H2O by gas chromatography of ignition products) is: MgO 0.28 wt%, CaO 0.47 wt%, ZnO 7.36 wt%, Al2O3 0.88 wt%, Fe2O3 42.42 wt%, P2O5 31.63 wt%, H2O 16.2 wt%, total 101.1 wt%. The empirical formula calculated on the basis of 27 oxygen atoms per formula unit is (Zn0.83Ca0.08Mg0.06)∑0.97(Fe3+ 4.88Al0.16)∑5.04(PO4)4.09(OH)4.78 · 5.86H2O. Zincoberaunite is monoclinic, space group C2/c; refined unit cell parameters (for the holotype at room temperature and the cotype at 100 K, respectively) are: a 20.837(2) and 20.836(4), b 5.1624(4) and 5.148(1), c 19.250(1) and 19.228(4) Å, β 93.252(5) and 93.21(3)°, V 2067.3(3) and 2059.2(7) Å3, Z = 4. The crystal structure of the holotype specimen has been refined by the Rietveld method (Rp = 0.30 %; RB = 0.18 %) whereas the structure of the cotype has been solved from the single crystal data and refined to R1 = 0.056 based on 1900 unique reflections with I > 2σ(I). The strongest reflections of the powder X-ray diffraction pattern of the holotype specimen [(d, Å) (I, %) (hkl)] are: 10.37 (100) (200), 9.58 (32) (002), 7.24 (26) (20–2), 4.817 (22) (111), 4.409 (13) (112), 3.483 (14) (11–4, 600), 3.431 (14) (404), 3.194 (15) (006, 31–4), 3.079 (33) (314).

Original languageEnglish
Pages (from-to)351-361
Number of pages11
JournalMineralogy and Petrology
Volume111
Issue number3
DOIs
StatePublished - 1 Jun 2017

Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

Keywords

  • Bavaria
  • Beraunite group
  • Crystal structure
  • Granitic pegmatite
  • Hagendorf South
  • Iron and zinc phosphate
  • New mineral
  • Zincoberaunite

Fingerprint

Dive into the research topics of 'Zincoberaunite, ZnFe<sup>3+</sup> <sub>5</sub>(PO<sub>4</sub>)<sub>4</sub>(OH)<sub>5</sub>⋅6H<sub>2</sub>O, a new mineral from the Hagendorf South pegmatite, Germany'. Together they form a unique fingerprint.

Cite this