Pinnoite mineral

Pinnoite is the magnesium hydroxyborate mineral MgB2O(OH)6 in the September 2026 IMA-CNMNC list. Its grandfathered status G and year 1884 describe its nomenclatural history, not a sequential approval identifier. It is distinct from chloropinnoite, other magnesium borate species, elemental boron and the borates commodity. Frost and Xi (2014) examined natural material supplied as pinnoite from the Inder boron deposit and salt dome, Kazakhstan. Their institutional author manuscript reports Raman spectra from at least ten crystals using 633-nm excitation and nominal 2 cm-1 resolution, and diamond ATR-FTIR spectra from 128 scans at 4 cm-1 resolution. Figures 2a, 3a and 4a show prominent Raman bands at 900 and 745 cm-1 and OH-region bands at 3179, 3399, 3554 and 3579 cm-1. These are specimen-level spectroscopic observations, not extraction yields or a new chemical-purity assay. The manuscript does not establish a complete bulk composition or report a new diffraction refinement for these crystals. Interpretation is limited by internal inconsistencies: manuscript page 5 says the OH-stretching region provides no water-band evidence, whereas page 7 assigns bands at 1629, 1665 and 1696 cm-1 to water bending and considers strongly adsorbed surface water. These passages do not establish occupied structural-water sites or justify changing the accepted ideal formula. The 745 cm-1 assignment differs between the results and conclusion; the infrared 3543 cm-1 value in the results differs from 3513 cm-1 in Figure 4b, abstract and conclusion. Hydrogen-bond distances are estimates from an empirical spectral correlation, not directly measured interatomic distances. Proposed nanomaterial uses were not tested as material performance. This characterization does not establish a microbial mechanism, recovered boron product, industrial deployment or jurisdiction-specific criticality designation.

Record source: data/records/pinnoite.yaml