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Ginorite mineral

Ginorite is the grandfathered calcium borate species listed as Ca2B14O20(OH)6(H2O)3·2H2O in the September 2026 IMA-CNMNC list. Its 1934 entry is a description year, not an approval identifier. The older Ca2[B14O20(OH)6]·5H2O formula has the same elemental stoichiometry. A natural Sasso Pisano crystal studied by Perchiazzi et al. has a monoclinic P21/a structure with borate sheets, calcium sites and hydrogen bonding; three water molecules per formula unit coordinate calcium and two do not. Hydrogen positions were refined with O-H distance restraints. The study's tabulated chemical analyses came from earlier publications, while its own preliminary SEM/EDAX screen found strontium below detection. This species is distinct from strontioginorite, elemental boron and the borates commodity. Neither a criticality designation nor microbial extraction or commercial recovery is inferred from its boron content.

Microbial & Biochemical Mechanisms (1)

Laboratory endothermic response on heating

other

Natural ginorite from Twenty Mule Team Canyon, Death Valley, showed an initial endothermic response at 70-80 degrees C and reported troughs at 100, 150, 310, 360 and 470 degrees C during differential thermal analysis. These are instrumental thermal features of that specimen, not identified product phases, an equilibrium decomposition sequence or a boron recovery yield.

Experimental Context & Analytical Limits:
Allen's 1957 procedure started with a cold furnace and used a nominal heating rate of 30 degrees C per minute through 500 degrees C. Samples were sieved to the reported -50+200 mesh range and lightly tamped in crucibles; ginorite was run at medium sensitivity. Temperature readings were taken at 10-degree intervals. Each mineral was analyzed at least three times, but individual ginorite replicate curves and statistical uncertainties were not reported. The mineral was checked microscopically, chemically and by X-ray diffraction before the thermal experiment. Sample mass, controlled atmosphere, evolved-gas analysis and post-run ginorite phase identification were not reported.
Curated Evidence Points:
The results table on p. 196 gives the onset range and five trough temperatures. Figure 20 on p. 198 explicitly labels the ginorite specimen's locality and plots its separate curve. Methods on pp. 194-195 and repeat-run statements on p. 196 constrain the instrumental context. The alumina-mixing and post-heating diffraction tests described for other named borates on p. 195 do not include ginorite and are not transferred to this arm.
The companion study documents Death Valley ginorite associated with sassolite and clay, purified by warm water dissolution of sassolite and drying at 105 degrees C. Table 1 retains an insoluble remainder and separates original from renormalized chemistry. The thermal report cites this characterization but does not establish that every thermal aliquot underwent the same drying protocol. Neither source measures a ginorite extraction efficiency or an isolated boron product.

Sources & References

  1. ima_2026_09: IMA-CNMNC, The New IMA List of Minerals, September 2026: PDF page 83, Ginorite row; page 1, status/year definitions. Fresh official list and current landing page checked on 16 October 2026. The coordinated-water notation preserves the total of five water molecules per formula unit.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-16)
  2. perchiazzi2016: Perchiazzi, Armienti, Iaccarino and Lezzerini (2016), A contribution to the mineralogy of the Larderello geothermal field. X-ray crystallographic studies on borate minerals bechilite and lagonite and crystal structure determination of ginorite, Atti della Societa Toscana di Scienze Naturali, Memorie Serie A 123, 79-87, DOI 10.2424/ASTSN.M.2016.23. Complete publisher article in institutional PDF, printed pp. 79-87 (PDF pp. 5-13): historical chemistry Table 2, diffraction Tables 3-6, methods p. 84 and Figures 3-4 p. 85. The natural crystal came from museum specimen 7678; this is not a synthetic or microbially formed specimen.
    https://iris.unito.it/retrieve/e27ce42c-6e27-2581-e053-d805fe0acbaa/009_PERCHIAZZI.pdf (accessed 2026-10-16)
  3. allen_kramer1957: Allen and Kramer (1957), Ginorite and sassolite from Death Valley, California, American Mineralogist 42, 56-61. Complete six-page original: locality pp. 56-57; warm-water removal of sassolite and 105-degree drying pp. 57-58; chemical analysis Table 1 p. 58; powder patterns Table 4 p. 60. Original and residue-corrected compositions are separate columns. This is a different specimen/locality from the later Italian and Kazakhstan structural studies.
    https://msaweb.org/AmMin/AM42/AM42_56.pdf (accessed 2026-10-16)
  4. allen_dta1957: Allen (1957), Differential thermal analysis of selected borate minerals, USGS Bulletin 1036-K, 193-208, DOI 10.3133/b1036K. Complete official report: apparatus/methods pp. 193-195; repeat runs and temperature summary p. 196; ginorite curve Figure 20 p. 198.
    https://pubs.usgs.gov/bul/1036k/report.pdf (accessed 2026-10-16)
  5. pankova2018: Pankova, Gorelova, Krivovichev and Pekov (2018), The crystal structure of ginorite, Ca2[B14O20(OH)6]·5H2O, and the analysis of dimensional reduction and structural complexity in the CaO-B2O3-H2O system, European Journal of Mineralogy 30, 277-287, DOI 10.1127/ejm/2018/0030-2695. Complete publisher PDF from the RRUFF repository: Chelkar sample and qualitative microprobe screening p. 279; structure Figures 1-2 p. 282. Abstract and Table 2 data row use 296(2) K, whereas methods and several table labels use 293 K; the second dataset is 150(2) K. Supplementary Tables S1-S3 were not acquired. Detailed thermal-expansion or hydrogen-bond measurements are therefore not imported. Its P21/c description and the earlier P21/a description are not treated as evidence of a phase transition; neither paper is a processing experiment.
    https://www.rruff.net/odr/view/downloadfile/83281 (accessed 2026-10-16)

Curation History

Timestamp Curator Action Summary
2026-10-16T04:26:58.244082Z codex (GPT-6; codex) CREATE Created a distinct ginorite species record with verified natural structure and bounded laboratory thermal response; retained specimen and source inconsistencies.

Record source: data/records/ginorite.yaml