Kernite mineral

Kernite is the Na2B4O6(OH)2·3H2O mineral species in the September 2026 IMA-CNMNC list, with grandfathered status G and original-description year 1927 rather than a sequential approval identifier. It is distinct from elemental boron, the broad borates commodity and the separately hydrated borax and tincalconite species. Gatta et al. characterized a natural Kramer Deposit, California, museum specimen by chemical analyses, single-crystal X-ray diffraction at 293 K and neutron diffraction at 20 K, supporting monoclinic P21/c kernite. Their Table 3 reports the specimen-specific empirical formula Na1.99B3.99O6(OH)2·3.01H2O and 50.90 +/- 0.20 wt% B2O3. Water at 26.40 +/- 0.20 wt% was estimated by treating the mass loss on heating to 800 degrees C as water, rather than being a separately measured recovery product. Table 2 reports Li2O below 0.01 wt%, and Table 1 reports rare-earth oxide signals below its element-specific detection limits; these censored observations neither mean zero nor establish the composition of all kernite deposits. The neutron refinement and maximum-entropy analysis favor static positional disorder for two water-hydrogen populations in this specimen, refining the older X-ray model rather than defining another species. Proton tunneling was not completely excluded. The two temperature refinements retained the same general structure, an endpoint comparison rather than a continuously measured stability interval. This identity and crystal-chemistry record does not adopt the paper's general criticality language, proposed industrial applications or inferred natural formation conditions as demonstrated extraction, microbial activity or deployment.

Record source: data/records/kernite.yaml