Donnayite-(Y) mineral

A sodium-strontium-calcium-yttrium carbonate mineral with the ideal IMA-CNMNC September 2026 formula NaSr3CaY(CO3)6(H2O)3. This mineral species is distinct from alicewilsonite-(YCe), a rare-earth element and a mixed ore. The authority lists renamed status and 1987 s.p.; that special-procedure year is not used here as a unique approval identifier. Lykova et al. (2023, Part 1) reexamined seven museum specimens catalogued as donnayite-(Y) cotypes from Mont Saint-Hilaire, Canada. Six were reassigned to alicewilsonite-(YCe); CMNMC 39396 was retained as donnayite-(Y) and designated its holotype under approved proposal 22-F. Historical data combined the two species and are not treated as a uniform donnayite dataset. Wavelength-dispersive electron-microprobe analyses of the holotype used 20 kV, 10 nA and a 30 micrometre beam with corrections for beam instability. Table 2 reports mean Y2O3 of 10.18 wt% across 17 analyses; H2O and CO2 were calculated from stoichiometry, not directly measured. These specimen assays are not extraction yields. The holotype's single-crystal refinement gave R1 = 0.139 and no satisfactory structural model. The reported triclinic P1 structure with R1 = 0.055 instead used the separate specimen CMNMC 90405 at 293 K. Its model has split carbonate and water positions, unlocated hydrogen, and Dy scattering proxies for lanthanides; it does not directly measure ideal stoichiometry. Published Table 5 gives Rint = 0.092 while the official CIF gives 0.0342 for the equivalent-reflection agreement field; that difference remains unresolved. The official CIF, powder pattern and supplementary bond-valence table were inspected without independent diffraction refinement. The curated evidence establishes natural identity and characterization, not a controlled microbial, extraction or recovery experiment. No criticality designation is transferred from contained elements.

Record source: data/records/donnayite-y.yaml