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Rozenite mineral

Rozenite is the monoclinic ferrous sulfate tetrahydrate mineral, Fe(II)(SO4)·4H2O, distinct from heptahydrate melanterite and monohydrate szomolnokite. The September 2026 IMA list recognizes it as a redefined species. The accepted primary experiment follows rozenite as a transient phase during laboratory heating of a natural melanterite sample. Phase fractions are diffraction-refinement results, not isolated-product recoveries or universal environmental stability limits. No microbial transformation is established by this experiment.

Microbial & Biochemical Mechanisms (1)

Rozenite as an intermediate in heated melanterite

other

In situ powder diffraction tracked rozenite formation during dehydration of natural melanterite and its subsequent loss as szomolnokite formed. Rozenite reflections persisted at 75 degrees C and disappeared in the pattern collected at 100 degrees C under the study's conditions. The starting ground powder already contained rozenite, so the experiment was not initiated with a pure melanterite phase or a pure rozenite feed.

Experimental Context & Analytical Limits:
Lacalamita et al., Materials and Methods, PDF page 3: the Fornovolasco mine specimen from Tuscany, Italy, was ground in an agate mortar and deposited on a corundum holder. In situ XRPD was performed in air from 25 to 775 degrees C in 25-degree steps with 5 min equilibration at each step. The diffraction range was 10-82 degrees 2theta; the stated step size was 0.0263 degrees and counting time 257 s/step. Discussion on PDF page 9 describes about 50% relative humidity for the room-temperature-to-50-degree transition; a controlled humidity series or complete high-temperature humidity history is not supplied. No inoculum, microbial control, independent heating replicate count, isolated product mass or recovery yield is reported.
Curated Evidence Points:
Section 3.2 on PDF pages 5-6, Figures 2-3 and Figure 7 on page 9 identify the phase sequence by XRPD and Rietveld analysis. The initial pattern was refined as 78% melanterite and 22% rozenite. These are refined phase weight fractions in that analyzed powder, not mineral yield percentages. Figure 7 and discussion on pages 9-10 place melanterite-to-rozenite conversion in the room-temperature-to-50 degrees C interval and rozenite disappearance by the 100-degree pattern. The phase is therefore a transient laboratory intermediate.
Section 3.2 on page 5 proposes grinding as the reason rozenite was already present at room temperature, using its reported absence from the mine. This is an interpretation, not a separately controlled grinding experiment. Discussion and Figure 8 on pages 9-10 explain dehydration in terms of replacement of water ligands by sulfate oxygen atoms and reorganization of hydrogen bonding; diffraction phase tracking does not directly observe each atomic reaction step.
Methods on page 3 and discussion on page 12 distinguish the in situ air-XRPD experiment from TG/DTA on about 13 mg in nitrogen at 10 degrees C/min. The original reports complete melanterite-to-rozenite dehydration at 50 degrees C by XRPD versus a roughly 70-degree DTA event; these protocol-dependent observations are retained rather than merged into one threshold. The work's infrared experiments used KBr pellets, pressed powders or a small crystal, with saturation and pellet-effect limitations described on pages 3 and 12. None of these measurements supplies a microbial mechanism or industrial recovery demonstration.

Sources & References

  1. ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026; Rozenite row on PDF page 188 and field definitions on pages 1-2. Fe2+(SO4)(H2O)4; status Rd, 1963 s.p. denotes a special-procedure redefinition year, not a new-mineral accession.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-15)
  2. handbook: Handbook of Mineralogy. Rozenite, version 1 (2001-2005), complete one-page entry. Monoclinic ferrous sulfate tetrahydrate; synthetic structural measurements and natural occurrences are distinguished.
    https://handbookofmineralogy.org/pdfs/rozenite.pdf (accessed 2026-10-15)
  3. lacalamita2021: Lacalamita, M., Ventruti, G., Della Ventura, G., Radica, F., Mauro, D. and Schingaro, E. (2021). In Situ High-Temperature X-ray Powder Diffraction and Infrared Spectroscopic Study of Melanterite, FeSO4·7H2O. Minerals 11(4), 392. DOI 10.3390/min11040392. Complete 15-page original, Table 1 and Figures 1-9 inspected.
    https://doi.org/10.3390/min11040392 (accessed 2026-10-15)

Curation History

Timestamp Curator Action Summary
2026-10-15T15:11:23Z codex (GPT-6; codex) CREATE Created rozenite from dated mineral authorities and the complete natural-melanterite thermal original, preserving mixed starting phases, proposed grinding effects and protocol-dependent abiotic transformation limits.

Record source: data/records/rozenite.yaml