Bastnaesite fluorocarbonate family mineral group
Bastnaesite, also spelled bastnäsite, is represented here as the fluorocarbonate family with ideal composition REE(CO3)F, encompassing the separately named bastnäsite-(Ce), -(La), -(Nd) and -(Y) species in the September 2026 IMA mineral list. This family-level record does not assert one member species or cover all hydroxyl-bearing or other members of the broader structural group. The experimental material below is a Ce- and La-rich natural mineral separate, not a pure endmember, a whole bastnaesite-bearing rock, an elemental rare earth, or a recovered commodity. Bulk oxide composition alone does not establish its member-species assignment. No constituent criticality designation is inherited.
Microbial & Biochemical Mechanisms (1)
Culture-associated rare-earth mobilization from a natural bastnaesite separate
bioleaching
Microbial
Associated Organisms:
Bacillus thuringiensis (NCBITaxon:1428)
Living Bacillus thuringiensis cultures mobilized rare-earth elements from a natural bastnaesite separate in laboratory shaking-flask assays. Culture acidification and organic-acid leaching experiments are consistent with proton- and ligand-promoted dissolution. The necessity of specific metabolites and the independent contribution of direct cell attachment were not established.
Experimental Context & Analytical Limits:
The wild isolate, called Bt, originated from the Renju regolith-hosted rare-earth deposit, Guangdong, China; no strain accession or culture deposit is supplied in the inspected main paper and supplement. The paper refers to an earlier isolation/identification study. Exponential-phase cells grown on LB plates were harvested, washed with sterile ultrapure water and resuspended in experimental medium. Mineral grains were selected from bastnaesite-bearing rock from Maoniuping, western Sichuan, China, crushed in agate, sieved to 48-74 micrometres, washed more than ten times and freeze-dried. Semiquantitative XRD assigned approximately 97 wt% bastnaesite and 3 wt% quartz; XRF reported 36.1 wt% CeO2, 30.1 wt% La2O3, 7.40 wt% Nd2O3 and 2.57 wt% Pr6O11. Triplicate 250 mL flasks contained 0.5 g mineral and 100 mL medium, with 100 microlitres of inoculum giving approximately 10^6 CFU/mL. Medium contained, per litre, 1.0 g MgSO4·7H2O, 0.2 g KCl, 1.0 g NH4Cl and 10 g glucose, initially pH 6; no P-containing reagent was added. Incubation was 30 days at room temperature and 180 rpm; no exact temperature is specified. Unbuffered Exp-Biow was compared with 20 mM MES Buffered-Biow, mineral-containing uninoculated controls and mineral-free cell cultures in both media. Methods call uninoculated arms Exp-Sterile and Buffered-Sterile; Results call them Exp-Control and Buffered-Control. Exp-bags enclosed mineral in a 10 kDa MWCO dialysis bag under otherwise unbuffered conditions. Aqueous elemental measurements used 0.22-micrometre filtration, dilution in 2% HNO3 and ICP-MS; this is an operational filtrate fraction, not a recovered-metal product. Cell counts represent planktonic cells and exclude mineral-attached cells.
The wild isolate, called Bt, originated from the Renju regolith-hosted rare-earth deposit, Guangdong, China; no strain accession or culture deposit is supplied in the inspected main paper and supplement. The paper refers to an earlier isolation/identification study. Exponential-phase cells grown on LB plates were harvested, washed with sterile ultrapure water and resuspended in experimental medium. Mineral grains were selected from bastnaesite-bearing rock from Maoniuping, western Sichuan, China, crushed in agate, sieved to 48-74 micrometres, washed more than ten times and freeze-dried. Semiquantitative XRD assigned approximately 97 wt% bastnaesite and 3 wt% quartz; XRF reported 36.1 wt% CeO2, 30.1 wt% La2O3, 7.40 wt% Nd2O3 and 2.57 wt% Pr6O11. Triplicate 250 mL flasks contained 0.5 g mineral and 100 mL medium, with 100 microlitres of inoculum giving approximately 10^6 CFU/mL. Medium contained, per litre, 1.0 g MgSO4·7H2O, 0.2 g KCl, 1.0 g NH4Cl and 10 g glucose, initially pH 6; no P-containing reagent was added. Incubation was 30 days at room temperature and 180 rpm; no exact temperature is specified. Unbuffered Exp-Biow was compared with 20 mM MES Buffered-Biow, mineral-containing uninoculated controls and mineral-free cell cultures in both media. Methods call uninoculated arms Exp-Sterile and Buffered-Sterile; Results call them Exp-Control and Buffered-Control. Exp-bags enclosed mineral in a 10 kDa MWCO dialysis bag under otherwise unbuffered conditions. Aqueous elemental measurements used 0.22-micrometre filtration, dilution in 2% HNO3 and ICP-MS; this is an operational filtrate fraction, not a recovered-metal product. Cell counts represent planktonic cells and exclude mineral-attached cells.
Curated Evidence Points:
Support
Source:
he_2025
Sections 2.1-2.3 and 3.2, Figure 5 (postprint p18) and Table 1 support increased aqueous REE in the inoculated mineral assays. At day 30, total REE concentrations were approximately 1698 micrograms/L in the unbuffered culture, 84 micrograms/L in the nominally pH-6 buffered culture, and 490 micrograms/L with mineral in dialysis bags. Unbuffered La and Ce were approximately 643 and 805 micrograms/L. Mineral-containing sterile and mineral-free culture controls were reported close to ICP-MS detection limits; no numerical detection limit is provided. These are solution concentrations, not percentages of mineral extracted or isolated-product yields.
Support
Source:
he_data_v1
Data5 day-30 rows reproduce the approximately 1698, 84 and 490 micrograms/L totals by summing La, Ce, Pr, Nd and the other-REE column. Data5 contains means and standard deviations for the three inoculated mineral arms; it does not supply quantitative rows for the sterile or mineral-free controls. The workbook corroborates the reported study and does not constitute an independent experiment.
Partial
Source:
he_2025
Figures 2-4 and 6 and Section 2.3.2 support acidification and the plausibility of ligand-promoted dissolution. The chemical assays used 0.1 g mineral in 20 mL HCl or selected organic-acid solutions, initial pH 3, 5 or 6, room temperature and 180 rpm for 96 hours. Their shorter duration and different solution matrix prevent treating them as fully matched 30-day abiotic comparators for the cultures. No metabolite-deletion or equivalent causal test establishes the necessity of a particular acid.
Partial
Source:
he_2025_supplement
Text S1 describes internal-standard-normalized UHPLC-MS metabolite annotations; these are relative signals, not calibrated culture molarities. Table S1 lists eight screened acids, seven tested because pelargonic acid was excluded as insoluble, plus additional tartaric and gluconic acids. Chemical leaching activity of an added acid therefore cannot be assigned quantitatively to its measured endogenous concentration.
Partial
Source:
he_data_v1
Data6 gives approximately 130.9 and 134.8 micrograms/L total REE after 96 hours with 20 micromolar tartaric and gluconic acid at initial pH 6, respectively, supporting the potential of stronger ligands. The main prose calls release by the seven initially selected acids at pH 6 absent, but Data6 contains low values up to approximately 2.8 micrograms/L and blanks; this is weak or near-background release, not demonstrated exact zero. Blank cells remain missing. The main pH-3 organic-acid range of approximately 1915-2180 micrograms/L also omits the Data6 crotonic-acid mean of approximately 1794 micrograms/L; the source discrepancy is unresolved.
Partial
Source:
he_data_v1
Data2 day-30 mean pH values are 3.7567 in Exp-Biow, 5.7567 in Buffered-Biow and 4.44 in Exp-bags. Thus nominally buffered pH 6 was not exactly constant. Section 3.1 describes late unbuffered pH as approximately 3.5, whereas Figure 2, the Figure 8 caption and Data2 are nearer 3.7. Data3 and Figure 2 also show an early unbuffered increase from approximately 1.23 million to 70 million CFU/mL, inconsistent with the Discussion's general statement that growth increments were less than one order of magnitude.
Partial
Source:
he_2025
Dialysis-bag cultures still mobilized REE, but had different pH and planktonic cell counts; bag transport may also differ. Their lower aqueous concentrations cannot quantify an isolated direct-contact effect. Figure 7 shows mineral-associated cells, etching and fine REE-bearing surface material. Similar EDS composition does not uniquely identify a new mineral phase; supplementary Figure S2 shows no obvious XRD phase change. Cell sorption and solid reprecipitation were not quantitatively separated, so no closed REE mass balance or isolated recovery is established.
Partial
Source:
he_2025
Feed estimates are not fully reconciled: Figure 1's semiquantitative approximately 3 wt% quartz differs from Table 1's bulk 0.635 wt% SiO2. These method-specific results are preserved without treating the feed as exactly 97% pure or assigning a formal species from its bulk oxides. The proposed retention of released REE by clays in natural weathering profiles is an inference from laboratory dissolution and literature comparisons, not a direct clay-adsorption assay or industrial deployment.
Sources & References
-
ima_2026_09: IMA-CNMNC, The New IMA List of Minerals, September 2026 edition; PDF p21, separate bastnäsite-(Ce), -(La), -(Nd) and -(Y) entries and formulas.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-11) -
he_2025: He, Ma, Li, Liu, Liang, Zhu and He (2025). Microbial-mediated bastnaesite dissolution as a viable source of clay-adsorbed rare earth elements in the regolith-hosted deposits. Geochimica et Cosmochimica Acta 394:43-52. DOI 10.1016/j.gca.2025.02.027. Complete 39-page GFZ institutional postprint; methods pp8-13, Figures 1-8, Tables 1-2 on p39, and Discussion pp18-30.
https://gfzpublic.gfz.de/pubman/item/item_5034287_3/component/file_5034752/5034287.pdf (accessed 2026-10-11) -
he_2025_supplement: He et al. (2025), supplementary material for DOI 10.1016/j.gca.2025.02.027; complete publisher PDF, 5 pages, Texts S1-S2, Table S1 and Figures S1-S2.
https://ars.els-cdn.com/content/image/1-s2.0-S001670372500105X-mmc1.pdf (accessed 2026-10-11) -
he_data_v1: He et al., research data for the bastnaesite dissolution study, Mendeley Data version 1, published 29 October 2024, DOI 10.17632/6n6d3fkkpc.1, CC BY 4.0. Complete ResearchData.xlsx inspected, sheets Data1-Data7. Data2 pH, Data3 planktonic cell counts, Data4 normalized metabolomics, Data5 aqueous REE, Data6 chemical leaching, Data7 SEM-EDX. These are supporting data from the same study, not independent replication.
https://data.mendeley.com/datasets/6n6d3fkkpc/1 (accessed 2026-10-11) -
ncbi_bt: NCBI Taxonomy 1428, Bacillus thuringiensis, species; authority information page inspected 11 October 2026. This identifier resolves the species name, not the study's unnamed wild isolate.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=1428&mode=Info (accessed 2026-10-11)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-11T17:45:52+00:00 |
codex (GPT-6; codex) | CREATE | Created a bastnaesite fluorocarbonate-family record with complete primary laboratory dissolution evidence, verified identity boundaries, original supporting data and explicit source discrepancies and causal limitations. |
Record source: data/records/bastnaesite.yaml