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Pertlikite mineral

Pertlikite is an approved tetragonal mineral of the voltaite group, IMA 2005-055, represented in the September 2026 IMA list as K2(Fe(II),Mg)2(Mg,Fe(III))4Fe(III)2Al(SO4)12(H2O)18. It is distinct from cubic voltaite and magnesiovoltaite, rather than a synonym for any magnesium-bearing voltaite-group material. Ertl et al. (2008) characterized natural type material from Madeni Zakh, Iran, using portions of a single crystal for diffraction, optical examination and electron-microprobe analysis, with additional grains for bulk hydrogen analysis. Tetragonal I41/acd symmetry and unequal Fe/Mg site occupancies distinguish the studied crystal from the cubic structural model. The formula combines microprobe chemistry, fitted Mossbauer spectral areas and structure refinement; it is not a direct assay of every site or oxidation state. Spectral areas were not corrected for different recoil-free fractions. Measured water was 15.3 wt.% with estimated 10% relative uncertainty, whereas 16.73 wt.% in the composition table was estimated from the structure. Powder and single-crystal cell dimensions differ beyond their stated precision, and hydrogen positions around disordered Al-bound waters were not located. A proposed origin through pyrite decomposition is geological interpretation, not an observed reaction or microbial mechanism. No extraction, recovery yield or criticality designation is curated.

Sources & References

  1. ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026; Pertlikite row on PDF page 169, approved status A and approval 2005-055; field definitions on pages 1-2. The listed formula distinguishes this species from cubic voltaite-group members.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-15)
  2. ertl2008: Ertl, A., Dyar, M. D., Hughes, J. M., Brandstatter, F., Gunter, M. E., Prem, M. and Peterson, R. C. (2008). Pertlikite, a new tetragonal Mg-rich member of the voltaite group from Madeni Zakh, Iran. The Canadian Mineralogist 46, 661-669. Complete nine-page original; type provenance and methods pages 662-665; Tables 1-8, Figures 1-5 and water/site-ordering discussion pages 666-669. Table 6 uses estimated water; Table 8 distinguishes powder and single-crystal cell values. Figure 3 labels the comparison voltaite 115035, whereas text and Table 5 use NMNH 115034; those comparison specimens are not additional pertlikite replicates. The separate deposited structure factors were not acquired or re-refined.
    https://doi.org/10.3749/canmin.46.3.661 (accessed 2026-10-15)
  3. ertl2008_archive: RRUFF document archive of Ertl et al. (2008), CM46_661.pdf, complete original pages 661-669. Same publication as ertl2008, not an independent experiment; the article reports type material in Vienna collection 7813 and a structure crystal at NMNH 174370. These are specimen references, not species identifiers.
    https://rruff.info/doclib/cm/vol46/CM46_661.pdf (accessed 2026-10-15)
  4. handbook_pertlikite: Handbook of Mineralogy. Pertlikite, revised January 10, 2022, complete one-page entry; species identity, tetragonal symmetry and type-material context based on Ertl et al. (2008). The primary article distinguishes measured from estimated water.
    https://handbookofmineralogy.org/pdfs/Pertlikite.pdf (accessed 2026-10-15)

Curation History

Timestamp Curator Action Summary
2026-10-15T18:27:58Z codex (GPT-6; codex) CREATE Created a distinct tetragonal mineral identity from the original type description, retaining water-assay, fitted spectral-area, site-ordering and specimen provenance limitations.

Record source: data/records/pertlikite.yaml