Whewellite mineral
Whewellite is the monoclinic calcium oxalate monohydrate mineral species Ca(C2O4)(H2O), distinct from weddellite, caoxite, calcium or phosphorus elements, and apatite-nepheline ore as a mixed resource. The September 2026 IMA list marks it approved with 1967 s.p.; that special-procedure notation is not a new-mineral accession. This record covers culture-associated whewellite and separate field-associated calcium oxalates from one 2019 study, without a recovery yield, industrial deployment or inherited constituent criticality.
Microbial & Biochemical Mechanisms (2)
Culture-associated whewellite on fluorapatite-rich rock
biomineralization
Microbial
Associated Organisms:
Aspergillus niger (NCBITaxon:5061)
Growing A. niger cultures were associated with whewellite crystallization on mixed apatite-nepheline rock. Diffraction and microscopy support a calcium-oxalate product; fungal acid secretion and host dissolution are proposed explanations rather than independently isolated causal steps.
Experimental Context & Analytical Limits:
Section 2.2 used source-named Aspergillus niger Ch4/07, isolated from damaged Proconesos marble at Chersonesos and identified using ITS sequence KF768341. The official record is KF768341.1, strain Ch 4/07; this correspondence is not independent authentication of the experimental stock. Conidia from a 10-day solid culture inoculated approximately 5 by 5 mm biofilm-free fragments of fluorapatite-rich apatite-nepheline rock from the sample-1 dump block, covered by 15 mL liquid Capek-Dox medium in Petri dishes. Experiments ran in triplicate at 20-25 degrees C for 2-15 days. The reported medium contains, in g/L, NaNO3 2.0, KH2PO4 1.0, MgSO4·7H2O 0.5, KCl 0.5, FeSO4·7H2O 0.01 and glucose 30.0. Initial pH 5.5 fell to 4.0 at day 5 and rose to 4.5 by the endpoint. Inoculum density, mineral mass, sterilization protocol and handling-dependent water content of harvested solids are not specified. No experiment used the sample-2 rock.
Section 2.2 used source-named Aspergillus niger Ch4/07, isolated from damaged Proconesos marble at Chersonesos and identified using ITS sequence KF768341. The official record is KF768341.1, strain Ch 4/07; this correspondence is not independent authentication of the experimental stock. Conidia from a 10-day solid culture inoculated approximately 5 by 5 mm biofilm-free fragments of fluorapatite-rich apatite-nepheline rock from the sample-1 dump block, covered by 15 mL liquid Capek-Dox medium in Petri dishes. Experiments ran in triplicate at 20-25 degrees C for 2-15 days. The reported medium contains, in g/L, NaNO3 2.0, KH2PO4 1.0, MgSO4·7H2O 0.5, KCl 0.5, FeSO4·7H2O 0.01 and glucose 30.0. Initial pH 5.5 fell to 4.0 at day 5 and rose to 4.5 by the endpoint. Inoculum density, mineral mass, sterilization protocol and handling-dependent water content of harvested solids are not specified. No experiment used the sample-2 rock.
Curated Evidence Points:
Support
Source:
frank_kamenetskaya_2019
Sections 2.2 and 3.4 report whewellite in all three culture replicates. Figure 3 trace 3 identifies whewellite in the day-5 culture product alongside retained substrate peaks; Figure 7 shows day-5 and day-12 surface products. The record concerns the identified calcium-oxalate component of a mixed sample, not a phase-pure isolated product or a measured conversion yield.
Partial
Source:
frank_kamenetskaya_2019
The paper supplies no matched uninoculated incubation outcome, killed-biomass arm or measured organic-acid series for this rock experiment. Biofilm-free starting rock is not such a control. Dissolution textures and pH change are compatible with fungal acid action but do not isolate the acid species, establish a molecular pathway or partition calcium sources. Figure 3 is a displayed pattern, not a replicate-level quantitative refinement; the record does not infer identical rates or phase fractions across the three replicates.
Partial
Source:
frank_kamenetskaya_2019
Sections 3.4 and 4 report only whewellite in the experimental oxalate products, unlike whewellite plus weddellite in field material. The cited marble experiments are separate studies, not matched substrate controls in this experiment. Differences in community, solution chemistry and handling prevent attributing the phase contrast solely to microbial community composition or substrate solubility.
Context_only
Source:
weddellite_handbook
The Handbook notes that weddellite can dehydrate to whewellite on atmospheric exposure. The 2019 study gives no in situ hydration monitoring or quantified storage/dehydration control, so original formation proportions and possible post-collection transformation remain unresolved; dehydration is not asserted to have occurred in these samples.
Context_only
Source:
genbank_ch407
The deposited ITS/ribosomal sequence is assigned to A. niger strain Ch 4/07 and agrees with the paper accession. It supports strain-name provenance, not an independently measured formation phenotype.
Context_only
Source:
ncbi_niger
NCBI 5061 resolves to Aspergillus niger at species rank; the identifier is not specific to Ch4/07.
Whewellite associated with natural lichen biofilms
biomineralization
Microbial
Whewellite was assigned with weddellite in natural lichen-associated material on fluorapatite-rich ore surfaces. The accepted observation is mineral occurrence and spatial association; the study does not identify which organism supplied oxalate or establish microbial necessity.
Experimental Context & Analytical Limits:
The 2018 field collection sampled biofilms on apatite-nepheline ore blocks from Khibiny massif dumps (sample 1) and the Kola Science Centre Rock Garden (sample 2). Thin sections and XRD identified mainly fluorapatite and nepheline with minor aegirine, titanite and titanomagnetite, rather than a pure mineral substrate. The authors associated calcium oxalates with fluorapatite-rich areas in thalli identified morphologically as Farnoldia jurana in sample 1 and Lecanora polytropa and Polysporina simplex in sample 2. These are mixed natural biofilms, not isolated-strain formation experiments; co-occurring micromycetes were also identified. Local crystallization pH, temperature, duration and metabolic state during formation were not measured. The separately cultivated A. niger strain is not assigned to those field specimens.
The 2018 field collection sampled biofilms on apatite-nepheline ore blocks from Khibiny massif dumps (sample 1) and the Kola Science Centre Rock Garden (sample 2). Thin sections and XRD identified mainly fluorapatite and nepheline with minor aegirine, titanite and titanomagnetite, rather than a pure mineral substrate. The authors associated calcium oxalates with fluorapatite-rich areas in thalli identified morphologically as Farnoldia jurana in sample 1 and Lecanora polytropa and Polysporina simplex in sample 2. These are mixed natural biofilms, not isolated-strain formation experiments; co-occurring micromycetes were also identified. Local crystallization pH, temperature, duration and metabolic state during formation were not measured. The separately cultivated A. niger strain is not assigned to those field specimens.
Curated Evidence Points:
Partial
Source:
frank_kamenetskaya_2019
Sections 2.1, 2.3-2.5 and 3.1-3.3, Table 2 and Figures 1-6 support source-assigned mixed whewellite/weddellite associated with lichen thalli. Figure 3 trace 2 explicitly represents Farnoldia jurana material; separate diffraction patterns for each of the other named lichens are not displayed. Figure 6 shows crystal-hypha association and source-assigned morphologies. The stated close proportions are not a quantitative phase refinement or a recovered-mass fraction.
Partial
Source:
frank_kamenetskaya_2019
The field association does not isolate a causal organism, demonstrate oxalate secretion by each lichen mycobiont, or trace calcium from a particular host phase. Discussion hypotheses about organic acids, Sr/Al impurities, citrate and community-dependent stabilization were not tested by matched community manipulations or dissolved-metabolite measurements in this study. Carbon-coated EDX spectra establish elemental context, not independently a crystal hydrate, valence or lattice-site substitution. No sterile field comparator, phase-specific extraction yield or industrial process is demonstrated.
Context_only
Source:
weddellite_handbook
Potential atmospheric dehydration of weddellite is a handling limitation. The field samples were not followed in situ from nucleation through collection, so no original phase ratio or compulsory transformation sequence is inferred.
Sources & References
-
ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Definitions pages 1-2; whewellite row page 234, A, 1967 s.p. Official list reopened and retained original row visually re-inspected on 14 October 2026.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-14) -
whewellite_handbook: Mineralogical Society of America, Handbook of Mineralogy. Whewellite, revised 1/6/2021 as printed. Complete one-page identity entry.
https://www.handbookofmineralogy.org/pdfs/Whewellite.pdf (accessed 2026-10-14) -
weddellite_handbook: Handbook of Mineralogy. Weddellite. Complete one-page entry, including atmospheric dehydration to whewellite. Identity and handling context, not an experiment on the 2019 specimens.
https://www.handbookofmineralogy.org/pdfs/weddellite.pdf (accessed 2026-10-14) -
frank_kamenetskaya_2019: Frank-Kamenetskaya, Olga V.; Ivanyuk, Gregory Yu.; Zelenskaya, Marina S.; Izatulina, Alina R.; Kalashnikov, Andrey O.; Vlasov, Dmitry Yu.; Polyanskaya, Evgeniya I. (2019). Calcium Oxalates in Lichens on Surface of Apatite-Nepheline Ore (Kola Peninsula, Russia). Minerals 9(11):656. DOI 10.3390/min9110656. Complete 13-page original inspected, including Figures 1-7 and Tables 1-2; PDF metadata dated 20 November 2019 agrees with the publisher updated-version entry.
https://doi.org/10.3390/min9110656 (accessed 2026-10-14) -
ncbi_niger: NCBI Taxonomy 5061. Aspergillus niger, species. Official taxonomy XML checked on 14 October 2026; species identity does not authenticate a strain.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=5061 (accessed 2026-10-14) -
genbank_ch407: NCBI GenBank KF768341.1. Aspergillus niger strain Ch 4/07 ribosomal/ITS sequence, isolation source grecian marble. Official sequence XML checked; accession labels a sequence, not a mineral or full genome.
https://www.ncbi.nlm.nih.gov/nuccore/KF768341.1 (accessed 2026-10-14)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-14T10:45:06.275870+00:00 |
codex (GPT-6; codex) | CREATE | Created whewellite species record with original 2019 calcium-oxalate evidence, separating field association from laboratory phase outcomes and preserving control, hydration and causal limits. |
Record source: data/records/whewellite.yaml