Pyrite mineral
Pyrite is the FeS2 mineral species listed with grandfathered status G in the September 2026 IMA compilation. Its row does not provide an approval identifier or a known original-description year. The species is distinct from iron, sulfur, marcasite, pyrrhotite, nickel-bearing substituted experimental phases and mixed ores. Natural specimen material and synthesized FeS2 used in the experiment below are separate assay substrates. No constituent-element criticality designation is inherited.
Microbial & Biochemical Mechanisms (1)
Methanogen growth on specimen pyrite with synthetic-phase reduction assays
redox transformation
Microbial
Associated Organisms:
Methanococcus voltae A3 (NCBITaxon:456320)
Living Methanococcus voltae A3 produced cells and methane with washed natural specimen pyrite as its added iron and sulfur source. Separate synthesized-FeS2 experiments produced sulfide and showed dependence on mineral accessibility, supporting culture-associated reductive transformation under these laboratory conditions. The natural specimen growth observation does not itself quantify its dissolution or establish the same reduction rate as the synthesized phase. No isolated-metal recovery or industrial deployment was demonstrated.
Experimental Context & Analytical Limits:
Payne et al. crushed Zacatecas, Mexico specimen pyrite from Ward's, selected the 63-125 micrometre fraction, and applied sequential hydrochloric acid, water and acetone washes. Natural specimen assays used 1.5 g per 75 mL medium, reported as 167 mM FeS2; synthesized-phase assays used 2 mM Fe. Loading was selected using estimated geometric surface areas, not measured equal reactivity. M. voltae A3, source ATCC BAA-1334, was washed and inoculated at 10% v/v into initially pH 7 defined basal medium with trace metals, vitamins, organic supplements and formate. The reported formate addition was 0.4% v/v of a 40% wt/v stock. Cultures used 165 mL serum bottles, 75 mL medium, an 80:20 N2/CO2 headspace pressurized to 3.14 atm, and static incubation at 38 degrees C. The specimen growth endpoint was day 5; the separate synthetic time course extended to day 7 and dialysis comparison used day 5. Biological arms were triplicate; the reported sulfide abiotic controls were single reactors. Direct counts, gas chromatography and methylene-blue sulfide analysis were used. The strain CURIE identifies A3, independently supported by NCBI and ATCC.
Payne et al. crushed Zacatecas, Mexico specimen pyrite from Ward's, selected the 63-125 micrometre fraction, and applied sequential hydrochloric acid, water and acetone washes. Natural specimen assays used 1.5 g per 75 mL medium, reported as 167 mM FeS2; synthesized-phase assays used 2 mM Fe. Loading was selected using estimated geometric surface areas, not measured equal reactivity. M. voltae A3, source ATCC BAA-1334, was washed and inoculated at 10% v/v into initially pH 7 defined basal medium with trace metals, vitamins, organic supplements and formate. The reported formate addition was 0.4% v/v of a 40% wt/v stock. Cultures used 165 mL serum bottles, 75 mL medium, an 80:20 N2/CO2 headspace pressurized to 3.14 atm, and static incubation at 38 degrees C. The specimen growth endpoint was day 5; the separate synthetic time course extended to day 7 and dialysis comparison used day 5. Biological arms were triplicate; the reported sulfide abiotic controls were single reactors. Direct counts, gas chromatography and methylene-blue sulfide analysis were used. The strain CURIE identifies A3, independently supported by NCBI and ATCC.
Curated Evidence Points:
Support
Source:
payne2021
Supplementary Figure S3a shows specimen-associated cell and methane production relative to cultures without added Fe/S. Figure 4b and supplementary Figures S7-S8 show cells associated with specimen grains. For the separate synthesized material, Figure 1a,c,e shows growth, methane and sulfide production; sulfide was not detected in the single abiotic control. Supplementary Figure S1 characterizes the synthesized phase by XRD; it does not show a separate specimen XRD pattern. These observations support the stated assay-specific growth and reduction interpretation.
Partial
Source:
payne2021
Figure 3 and supplementary Table S3 compare accessible versus 3.5 kDa membrane-sequestered synthesized FeS2. At day 5, accessible mineral supported cell and methane production and 10.55 +/- 0.13 micromol total sulfide, reported as mean +/- SD for three biological replicates. Sequestered, unamended and abiotic arms had sulfide below detection, not measured zero. This does not distinguish contact-dependent electron transfer from access to products or large extracellular assemblies. Acid-labile Fe(II) remained below the approximately 11 micromolar assay limit. Secondary mackinawite or pyrrhotite formation and the molecular uptake pathway were proposed, not phase-confirmed products or a closed mineral mass balance. The cell-based reduction estimate combines measurements with assumptions and is not a directly measured extraction yield. Supplementary Figure S6 also shows growth with added sulfide alone, consistent with trace iron in the medium.
Context_only
Source:
payne2021
Original supplementary Data Set 1, sheet Figure 1 CH4 and Sulfide Values, labels E23 as total methane in mmol and H24 as Unamended, but H26:H32 reference the neighboring pyrite standard-deviation cells G26:G32 multiplied by 1000. H26 has an explicit formula and H27:H32 use a shared formula; cached H29 is 225.334939 mmol, inconsistent with the near-zero unamended curve in Figure 1c. This workbook block cannot independently validate the plotted control methane values and is not imported as measurements or silently repaired. The separate natural specimen Figure S3 and dialysis Table S3 are not this workbook block.
Context_only
Source:
payne2021
The companion Methanosarcina barkeri arm is not pooled with A3 or assigned a strain CURIE here. The paper labels it MS but gives ATCC BAA-2329. Its printed main-medium recipe also conflicts with supplementary Table S2, including NaCl 1.0 versus 29.22 g/L and MgCl2 hexahydrate 0.4 versus 10.17 g/L. The actual strain and recipe remain unresolved. Natural specimen and synthetic endpoints, FeS controls and dialysis data are separate experiments; their numbering inconsistencies do not justify merging them or transferring assay values between substrates.
Partial
Source:
atcc_baa2329
The issuing collection identifies BAA-2329 as Fusaro, while the primary paper calls the culture MS. This limits strain-level transfer of the companion result without deciding which label describes the cells actually tested. It does not invalidate the separately identified A3 arm.
Sources & References
-
ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. PDF page 179, Pyrite row; pages 1-2, column definitions and distribution terms.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-11) -
payne2021: Payne, Spietz and Boyd (2021). Reductive dissolution of pyrite by methanogenic archaea. The ISME Journal 15:3498-3507. DOI 10.1038/s41396-021-01028-3. Materials and methods, Results and discussion, Figures 1-4; original supplementary Figures S1-S8, Tables S1-S3 and Data Set 1.
https://doi.org/10.1038/s41396-021-01028-3 (accessed 2026-10-11) -
ncbi_voltae_a3: NCBI Taxonomy 456320, Methanococcus voltae A3, strain node.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=456320 (accessed 2026-10-11) -
atcc_baa1334: ATCC BAA-1334, Methanococcus voltae; strain designation A3.
https://www.atcc.org/products/baa-1334 (accessed 2026-10-11) -
atcc_baa2329: ATCC BAA-2329, Methanosarcina barkeri; strain designation Fusaro, documenting a discrepancy with the 2021 paper's MS label.
https://www.atcc.org/products/baa-2329 (accessed 2026-10-11)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-11T20:30:16.005497+00:00 |
codex (GPT-6; codex) | CREATE | Curated IMA pyrite identity with separate natural-specimen growth and synthetic-phase reduction evidence; retained source, control and strain limits. |
2026-10-11T20:38:07.705435+00:00 |
codex (GPT-6; codex) | EDIT | Retained the original workbook control-methane formula discrepancy identified by independent review F1 and issue 115, without repairing source data. |
Record source: data/records/pyrite.yaml