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Hollandite mineral

Hollandite is the barium manganese oxide mineral with IMA-CNMNC formula Ba(Mn4+6Mn3+2)O16 in the September 2026 list, which records redefined status and a 2012 special procedure. The mineral species is distinct from the broader hollandite structure family, elemental manganese, manganese ore and manganese oxalates. No criticality designation is inherited from manganese or barium.

Microbial & Biochemical Mechanisms (1)

Culture-associated manganese oxalate formation on a hollandite-labelled specimen

biomineralization Microbial

Associated Organisms: Serpula himantioides (NCBITaxon:80602), Coniophora puteana (NCBITaxon:80637), Serpula lacrymans (NCBITaxon:85982), Amyloporia xantha (NCBITaxon:1333629)

Three brown-rot fungal cultures incubated with a source-identified hollandite specimen produced surface solids assigned to manganese oxalate phases. The experiment supports culture-associated secondary crystallization on this feed. Source phase assignments, especially the Coniophora puteana dihydrate assignment, have method-dependent limits. It does not establish a measured manganese reduction pathway, complete hollandite conversion, barium recovery or an isolated oxalate yield.

Experimental Context & Analytical Limits:
Table 3 describes entangled fibrous, reniform hollandite aggregates from the U. M. Bronzova collection, with possible Fe impurity no greater than 1.35 wt% FeO. Its formula Ba(Mn2+,Mn4+)8O16 differs from the current IMA species formula Ba(Mn4+6Mn3+2)O16. The paper reports starting-material PXRD/EDX but no specimen-specific valence or site-occupancy refinement. The assay feed therefore remains source-identified hollandite, not independently demonstrated ideal endmember material. Methods 2.2 describes approximately 1 x 0.5 x 0.5 cm blocks in plastic Petri dishes with 20 mL liquid glucose-peptone medium, initial pH 5.5, room temperature and 30 days, in triplicate. Mycelial fragments came from ten-day cultures on glucose-peptone agar. Inoculum amount, substrate sterilization and a separate complete liquid-medium formulation are not specified. The paper names Antrodia xantha; current NCBI taxonomy and its cited ribosomal accession use Amyloporia xantha for LE-BIN 1029. The organisms list includes the tested comparator S. lacrymans; it does not assert identical mineral formation by every listed culture.
Curated Evidence Points:
Table 4 lists falottaite and lindbergite by SEM/EDX and PXRD for Serpula himantioides LE-BIN 1368 at pH 3, and lindbergite plus whewellite by both methods for source-named Antrodia xantha LE-BIN 1029 at pH 2. Figures 6a and 7a show source-assigned manganese-oxalate morphologies. The assignments refer to mixed recovered surface products; no quantitative phase fractions or separate manganese mass balance is provided.
For C. puteana LE-BIN 1370 at pH 5, Table 4 lists falottaite and lindbergite by SEM/EDX but only falottaite by PXRD. Figure 3e instead captions its diffraction trace as falottaite and lindberghite, and Figure 7a names both phases in microscopy. That Table 4/Figure 3 conflict prevents claiming an unambiguous diffraction-confirmed C. puteana lindbergite product. S. lacrymans LE-BIN 1192 has dashes including pH; those are not measured zero yields. Source preparation and hydration-state handling are not specified for each arm, and no hollandite-specific sterile product pattern or manganese oxidation-state series is supplied.
Methods states that fungus-free controls were performed, but the selected mineral-arm results do not provide a matched pH-control series or a quantitative inoculated-versus-uninoculated phase balance. No killed-biomass or cell-free-metabolite comparison isolates a necessary causal step. Oxalate secretion is the proposed explanation, without an arm-specific oxalate time course or molecular intervention in this study. PXRD methods are referred to earlier papers; the displayed patterns include substrate peaks. Culture association and source-assigned phases do not establish quantitative microbial enhancement, complete feed consumption or industrial use.
Context_only Source: vlasov2023
This is one arm of Vlasov et al. (2023), also represented by the humboldtine record and separately curated mineral-feed owners. The shared paper, its XML/PDF and the different material views are not independent replications. Its comparison with earlier Aspergillus niger studies uses different protocols and does not establish superior extraction rates for the present cultures. The natural adit observations concern calcium oxalates on wood/carbonate rock; they do not establish field deployment of this particular feed transformation.
Context_only Source: ima_2026_09
The authority establishes the mineral species name and formula, not the purity, valence, hydration or transformation behavior of the specific experimental material.
Species taxonomy verifies identifiers and current names. A species TaxID does not identify the experimental strain or demonstrate its mineral-transforming phenotype.
The deposited sequence carries the Serpula himantioides LE-BIN 1368 source label cited by the paper. This label/sequence match is not independent authentication of the experimental culture or direct evidence for the mechanism.
The deposited sequence carries the Coniophora puteana LE-BIN 1370 source label cited by the paper. This label/sequence match is not independent authentication of the experimental culture or direct evidence for the mechanism.
The deposited sequence carries the Serpula lacrymans LE-BIN 1192 source label cited by the paper. This label/sequence match is not independent authentication of the experimental culture or direct evidence for the mechanism.
The deposited sequence carries the Amyloporia xantha LE-BIN 1029 source label cited by the paper. This label/sequence match is not independent authentication of the experimental culture or direct evidence for the mechanism.

Sources & References

  1. ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Hollandite row, PDF page 95; introductory column definitions and distribution terms.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-12)
  2. vlasov2023: Vlasov, Zelenskaya, Izatulina, Janson and Frank-Kamenetskaya (2023). Oxalate Crystallization under the Action of Brown Rot Fungi. Crystals 13:432. Complete main article; Methods 2.2-2.3, Tables 2-4 and mineral-specific Figures 3-7.
    https://doi.org/10.3390/cryst13030432 (accessed 2026-10-12)
  3. ncbi_fungal_taxonomy: NCBI Taxonomy. Species nodes 80602, 80637, 85982 and 1333629; current names and species ranks.
    https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=taxonomy&id=80602,80637,85982,1333629&retmode=xml (accessed 2026-10-12)
  4. genbank_ky352492_1: NCBI GenBank KY352492.1. Ribosomal sequence and source strain label Serpula himantioides LE-BIN 1368; identity context only.
    https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=nuccore&id=KY352492.1&rettype=gb&retmode=text (accessed 2026-10-12)
  5. genbank_ky433978_1: NCBI GenBank KY433978.1. Ribosomal sequence and source strain label Coniophora puteana LE-BIN 1370; identity context only.
    https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=nuccore&id=KY433978.1&rettype=gb&retmode=text (accessed 2026-10-12)
  6. genbank_ky352493_1: NCBI GenBank KY352493.1. Ribosomal sequence and source strain label Serpula lacrymans LE-BIN 1192; identity context only.
    https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=nuccore&id=KY352493.1&rettype=gb&retmode=text (accessed 2026-10-12)
  7. genbank_ky433983_1: NCBI GenBank KY433983.1. Ribosomal sequence and source strain label Amyloporia xantha LE-BIN 1029; identity context only.
    https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=nuccore&id=KY433983.1&rettype=gb&retmode=text (accessed 2026-10-12)

Curation History

Timestamp Curator Action Summary
2026-10-12T00:16:05Z codex (GPT-6; codex) CREATE Added current IMA hollandite identity with narrowly qualified culture-associated manganese oxalates, retaining the feed-formula mismatch, method-dependent phase conflict and absent redox and recovery measurements.

Record source: data/records/hollandite.yaml