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Ludlamite mineral

Ludlamite is the ferrous phosphate mineral with ideal formula Fe2+3(PO4)2(H2O)4, recorded as grandfathered in the September 2026 IMA list. It is a distinct mineral species from the three-water phosphoferrite and eight-water vivianite. Moore (1971) investigated natural ludlamite crystals from the Palermo number 1 mine in an abiotic heating comparison. The lower-temperature arms retained the starting powder pattern, whereas the 240 degrees C arm gave a ferric product with diffuse diffraction unrelated to the initial mineral. This observation does not identify a pure crystalline product or establish a general transformation temperature for all ludlamite specimens. The ludlamite and phosphoferrite observations curated in this corpus are different mineral arms of the same study, not independent replications. No microbial process, isolated-product recovery or constituent-derived criticality designation is asserted.

Microbial & Biochemical Mechanisms (1)

Abiotic heating-associated oxidation of natural ludlamite

redox transformation

Moore (1971) reports superficial oxidation and unchanged powder diffraction after five days at 120 or 180 degrees C in air. At 240 degrees C for five days, the product was reported to contain iron only in the ferric state, with diffuse powder lines unrelated to the initial ludlamite. The ferric assay and loss of the original diffraction pattern support a qualified thermal oxidation observation. They do not identify the product mineral, quantify a phase-pure yield or demonstrate the proposed structural explanation for instability.

Experimental Context & Analytical Limits:
Natural crystals from the Palermo number 1 mine were heated in open capillaries at 120, 180 and 240 degrees C for five days, with a chromel-alumel thermocouple touching the crystals. Products were quenched to room temperature, dissolved in cold HCl and titrated against potassium dichromate; powder diffraction was compared with starting material. The source provides no separate quantitative composition for these ludlamite aliquots, sample masses, replicate counts, conversion uncertainty or mass balance. The stated starting-pattern comparison is not a displayed matched untreated time-course control. Vivianite and phosphoferrite are different-mineral comparisons, and no oxygen-free ludlamite arm isolates the role of atmospheric oxygen. This is a laboratory observation with no extraction or recovery assay.
Curated Evidence Points:
Page 14 directly reports the natural-crystal provenance, air/capillary procedure, temperatures, five-day duration, quench, HCl/dichromate analysis and distinct outcomes for the ludlamite arms. The lower-temperature retention of diffraction is preserved alongside the 240 degrees C ferric outcome. Pages 15-16 interpret structural instability; the hypothetical oxidized ludlamite formula is not an identified product. Figure 7 is a phosphoferrite-kryzhanovskite-reddingite diagram and does not supply a quantitative ludlamite result. The proposed hydrogen-release test on page 16 concerns phosphoferrite and is not a measured ludlamite pathway.

Sources & References

  1. ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Ludlamite row, PDF page 129: Fe2+3(PO4)2(H2O)4, G; status definitions page 1.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-15)
  2. moore1971: Moore PB (1971). The Fe2+3(H2O)n(PO4)2 homologous series: crystal-chemical relationships and oxidized equivalents. American Mineralogist 56:1-17. Complete original. Ludlamite heating methods and results, Oxidation Sequences page 14; structural interpretation pages 15-16. Table 1 page 2 reuses earlier ludlamite cell data; Figure 7 page 15 concerns other mineral arms.
    https://www.rruff.net/doclib/am/vol56/AM56_1.pdf (accessed 2026-10-15)

Curation History

Timestamp Curator Action Summary
2026-10-15T16:15:51.100094Z codex (GPT-6; codex) CREATE Created a distinct ludlamite mineral record with qualified natural-crystal thermal oxidation evidence, preserving lower-temperature outcomes, shared-study lineage and uncharacterized product limits.

Record source: data/records/ludlamite.yaml