Monazite-(Sm) mineral

Monazite-(Sm) is the samarium-dominant monazite mineral species with ideal formula Sm(PO4), distinct from elemental samarium, hydrated samarium phosphates, other monazite species and mixed rare-earth ores. The September 2026 IMA-CNMNC list assigns approved status and number 2001-001. The original description instead prints 2000-001; the current authority is followed here while retaining that source discrepancy. Masau et al. (2002) characterized natural crystals from the Annie Claim #3 granitic pegmatite in southeastern Manitoba, Canada, by wavelength-dispersive electron-microprobe analysis, optical examination, single-crystal diffraction and Gandolfi powder diffraction. The diffraction data support monoclinic P21/n symmetry. The analyzed natural material contains substantial Gd, Ce, Th and Ca and is not a pure SmPO4 end-member. Table 1 reports 13.02 wt% Sm2O3 for the average of three grains used for physical, optical and crystal data; its 14.29 wt% maximum belongs to a different analysis, not one of those extracted grains. These are mineral oxide compositions, not a bulk ore grade or recovered samarium yield. Density and hardness could not be measured; the reported densities are calculated. Selective rare-earth complexation during pegmatite crystallization is a proposed geological explanation, not an experimentally demonstrated extraction or formation mechanism. This natural characterization does not establish microbial biomineralization, recovery performance, industrial deployment or a jurisdiction-specific criticality designation.

Record source: data/records/monazite-sm.yaml