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Kaliborite mineral

Kaliborite is the grandfathered potassium-magnesium borate species KHMg2B12O16(OH)10(H2O)4 in the September 2026 IMA-CNMNC list. Its 1889 entry is an original-description year, not an approval identifier. Burns and Hawthorne studied a natural Kazakhstan crystal from Canadian Museum of Nature specimen 53372 and refined a monoclinic C2/c structure with borate chains parallel to b. Their 1994 study located hydrogen by difference-Fourier analysis with O-H distance restraints. The apparently symmetric hydrogen bond was interpreted as dynamically disordered from structural and bond-valence arguments; this was not a direct measurement of hydrogen motion. The paper did not provide a new bulk chemical analysis of that crystal. A separate museum material supplied the thermal experiments below. This mineral is distinct from elemental boron and the borates commodity; neither criticality, microbial activity nor industrial recovery is inferred.

Microbial & Biochemical Mechanisms (1)

Laboratory thermal amorphization and recrystallization

other

Heating natural kaliborite produced an X-ray-amorphous solid during water and hydroxyl loss, followed by crystallization of magnesium borates and subsequently a potassium borate. These are reported laboratory phase transformations, not a measured boron extraction efficiency or recovery of an isolated product.

Experimental Context & Analytical Limits:
Stoch and Waclawska used coarse-crystalline natural borate minerals described as pure from the Mineralogical Museum of Wroclaw University; they did not give a kaliborite accession, locality, quantitative purity or composition analysis. Thermal analysis used Q-1500D and C-derivatographs. For the structural examination arm, samples were heated at 2.5 degrees C per minute to characteristic temperatures, cooled and examined by powder X-ray diffraction and infrared spectroscopy. That stated ramp is not assigned here to every DTA/TG run. Sample mass, atmosphere, hold times and replicate counts are not specified.
Curated Evidence Points:
The kaliborite results on pp. 183-185 report thermal events at 258 and 272 degrees C and progressive water/OH release through 400 degrees C. Table 1 assigns an amorphous state at 400 degrees C and recrystallization at 679 degrees C; Figure 2a(C) distinguishes the original, amorphous and two recrystallized powder patterns. Magnesium-borate reflections are assigned to MgB4O7 and Mg2B2O5, with KB5O8 in the later recrystallized pattern. Table 1 places that later step at 729 degrees C and melting at 954 degrees C. The evidence identifies phases, without quantitative product fractions.
The 640-degree endotherm is interpreted as a glass-transition effect, rather than directly establishing a useful glass product. Tables 1 and 4 print different amorphous bulk formulas, so neither is adopted as a balanced reaction or measured composition. The reported temperatures are features of the authors' heating experiments, not demonstrated equilibrium boundaries. This article cites the same authors' 1993 kaliborite study as reference 5; the two publications are not counted as independent replication. The complete 1993 paper was not acquired, and its abstract's inconsistent dehydration/dehydroxylation ordering is not imported.

Sources & References

  1. ima_2026_09: IMA-CNMNC, The New IMA List of Minerals, September 2026: PDF page 107, Kaliborite row; page 1, status/year definitions. Official list and current CNMNC landing page checked on 16 October 2026; status G, original-description year 1889.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-16)
  2. burns_hawthorne1994: Burns and Hawthorne (1994), Kaliborite: An example of a crystallographically symmetrical hydrogen bond, Canadian Mineralogist 32, 885-894. Complete ten-page author-hosted original: specimen/methods pp. 886-888, Tables 1-4, structure Figures 1-4, H-site alternative and Figure 5 pp. 892-893, IR Figure 6 p. 893. The prose reports 3642 total reflections while Table 1 reports 3842; neither total is treated as reconciled. The split-H model did not improve the R index.
    https://www.frankhawthorne.com/_files/ugd/70a3a9_67d71ad6321c4de5b0ab57d834335ee7.pdf (accessed 2026-10-16)
  3. cod_9004342: Crystallography Open Database 9004342, live CIF retrieved 16 October 2026, revision 303136 dated 1 November 2025. This derivative of AMCSD 0005415 identifies the Burns and Hawthorne 1994 structure, formula B12 H19 K Mg2 O30 and C 1 2/c 1 symmetry. It is a structure accession, not an IMA species-approval number or a new experimental replicate. Original measured structure-factor data were not acquired.
    https://www.crystallography.net/cod/9004342.cif (accessed 2026-10-16)
  4. stoch_waclawska1994: Stoch and Waclawska (1994), Phase Transformations in Amorphous Solids, High Temperature Materials and Processes 13(3), 181-202, DOI 10.1515/HTMP.1994.13.3.181. Complete 22-page national-library PDF, including final blank page: materials and methods p. 183, Table 1 p. 184, results/Figure 1 p. 185, kaliborite powder patterns Figure 2a(C) p. 186, interpretation pp. 190 and 194, Table 4 p. 196, reference 5 p. 200. Crossref confirms 1994 publication, rather than the later posting date shown by some discovery services.
    https://d-nb.info/1354420837/34 (accessed 2026-10-16)

Curation History

Timestamp Curator Action Summary
2026-10-16T06:52:26.196530Z codex (GPT-6; codex) CREATE Created kaliborite species identity and bounded laboratory thermal phase-change evidence, retaining specimen and source-formula limits.

Record source: data/records/kaliborite.yaml