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Chrysotile mineral

Chrysotile is the Mg3Si2O5(OH)4 serpentine mineral species, redefined under the 2007 special procedure in the September 2026 IMA list. It is distinct from lizardite, magnesium element, asbestos as a collective material term and chrysotile asbestos mill tailings. The reviewed experiment used a prepared natural chrysotile sample with nonideal composition, not an assumed pure end member. No constituent criticality designation is inherited.

Microbial & Biochemical Mechanisms (1)

Thermovibrio dissolution assay with no demonstrated magnesium or silicon release advantage

bioleaching Microbial

Associated Organisms: Thermovibrio ammonificans (NCBITaxon:228745)

Thermovibrio ammonificans cultures containing chrysotile showed silicon associated with mapped biomass, interpreted by the authors as biosilicification. The matched mineral-medium controls also released magnesium and silicon; the study did not establish enhanced bulk release due to the microorganism. This is a tested microbial interaction with a null enhancement result, not evidence of effective bioextraction.

Experimental Context & Analytical Limits:
Choi et al. used 1 g/L prepared chrysotile, 25 mL Mg/Ca-free modified SME medium, 75 degrees C, pH 5.5, 2 wt% NaCl and H2/CO2 (80:20 by volume, 0.2 MPa), with about 20 mM KNO3 as terminal electron acceptor. One-week experiments were triplicate, with mineral-free cultures and uninoculated mineral-medium controls. Magnesium carried with the inoculum from the original growth medium required correction. The cited preparation method uses Balangero chrysotile, wet grinding in 2-propanol, sequential nylon-mesh filtration and autoclaving; its nominal 5-20-micrometre fraction is not a verified length interval for every fibre. Culture strain provenance and exact batch purity are not independently authenticated. Aqueous analyses used centrifuged 0.2-micrometre filtrates; electron microscopy used washed, air-dried solids.
Curated Evidence Points:
Results, Figure 2B and Conclusions explicitly fail to demonstrate the proposed enhancement of magnesium and silicon release by this Thermovibrio culture under these conditions. Similar release occurs without cells. Figure 3D-F shows altered particle tips in both arms with retained crystallinity; it does not show microbial fibre destruction.
Figure 4A shows overlapping Si and biomass-associated C/N maps, compatible with the authors' biosilicification interpretation but not a quantified silica product, intracellular uptake or a cause of accelerated mineral dissolution. Text concentrations, Figure 2B bars and the described inoculum-magnesium correction do not transparently reconcile; Methods additionally describe negative-control subtraction without fully specifying its relation to displayed control series. The supplement was unavailable, so exact dissolved yields, rates and source-table measurements are not adopted. No detoxification or industrial recovery is demonstrated.
Context_only Source: vigliaturo2020
The preparation method cited by Choi identifies the Balangero origin and processing. Its dimensional analysis could not reliably measure chrysotile fibre length because of curvature and bundling, so its aspect-ratio preservation is not assumed to be demonstrated for every chrysotile fibre. This methods study is not an independent bioleaching experiment.
Context_only Source: pollastri2016
Table 2 gives the Balangero nonideal composition quoted by Choi; Table 3 records accompanying minerals in the characterized source sample. This supports retaining impurity and composition limits, without assigning these earlier sample proportions to the exact 2023 experimental batch.

Sources & References

  1. ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026; pages 1-2 definitions, Chrysotile row PDF page 45 and Riebeckite row PDF page 185.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-14)
  2. choi2023: Choi, Vigliaturo, Giere and Perez-Rodriguez (2023). Microbe-Mineral Interactions between Asbestos and Thermophilic Chemolithoautotrophic Anaerobes. Applied and Environmental Microbiology 89(6):e02048-22. DOI 10.1128/aem.02048-22; complete PMC main text and Figures 1-4 inspected; supplement not acquired.
    https://doi.org/10.1128/aem.02048-22 (accessed 2026-10-14)
  3. vigliaturo2020: Vigliaturo, Choi, Perez-Rodriguez and Giere (2020). Dimensional distribution control of elongate mineral particles for their use in biological assays. MethodsX 7:100937. DOI 10.1016/j.mex.2020.100937; sample provenance, grinding/filtration and sterilization methods; chrysotile length-measurement limitation.
    https://doi.org/10.1016/j.mex.2020.100937 (accessed 2026-10-14)
  4. pollastri2016: Pollastri et al. (2016). The crystal structure of mineral fibres 1. Chrysotile. Periodico di Mineralogia 85:249-259. DOI 10.2451/2016PM655; Tables 1-3 and sample preparation, pages 251-253.
    https://doi.org/10.2451/2016PM655 (accessed 2026-10-14)
  5. ncbi_thermovibrio: NCBI Taxonomy 228745, Thermovibrio ammonificans, species; official taxonomy XML checked 14 October 2026. Species grounding does not establish strain identity for this assay.
    https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=228745&mode=Info (accessed 2026-10-14)

Curation History

Timestamp Curator Action Summary
2026-10-14T09:21:29.026997+00:00 codex (GPT-6; codex) CREATE Created mineral species record from primary thermophile assay evidence, with control outcomes, preparation limits and unresolved supplementary-data questions.

Record source: data/records/chrysotile.yaml