Florencite-(La) mineral

Florencite-(La) is the lanthanum-dominant aluminium phosphate mineral with ideal formula LaAl3(PO4)2(OH)6, distinct from florencite-(Ce), other florencite species, elemental lanthanum and mixed rare-earth ores. The September 2026 IMA list records renamed status and the 1987 special procedure; this is not a numbered species accession or a critical-material designation. Lefebvre and Gasparrini (1980) characterized natural La-rich grains in a Shituru drill-core siltstone, using electron-microprobe chemistry, optical properties and powder diffraction. The Shituru analysis has La as the dominant measured rare earth; Pr was detected qualitatively but not quantified, and water was not measured. Reported rare-earth proportions therefore are not a complete independently measured end-member formula. The diffraction pattern from an extracted 60-micrometre crystal supported florencite identity, while a mixed hematite-florencite concentrate gave only one attributable reflection. The origin was interpreted from geology, with hydrothermal and later supergene alternatives; no controlled formation experiment was performed. Ghignone et al. (2024) separately examined a collection specimen F1 from Igarape Bahia, Brazil. Its unpolished, uncoated SEM-EDS measurements are explicitly semiquantitative, with an oxide total of 35.6 wt%, and cannot be treated as a complete bulk assay or proof of a pure La end-member. The measured Raman spectra of compositionally different florencites are similar; Raman matching alone cannot resolve the dominant rare-earth species. The computed ideal La structure and vibrational modes are models, not a new experimental single-crystal refinement of F1. No microbial mechanism, recovery yield, dated criticality claim or industrial deployment is established by these characterization studies.

Record source: data/records/florencite-la.yaml