Xenotime-(Yb) mineral

Xenotime-(Yb) is the ytterbium-dominant xenotime mineral with ideal formula Yb(PO4), approved as IMA 1998-049. It is distinct from elemental ytterbium, xenotime-(Y), xenotime-(Gd) and mixed xenotime concentrates. Buck et al. (1999) described microscopic natural grains in ferrian muscovite aggregates from the SHE-5 pegmatite of the Shatford Lake group, southeastern Manitoba, Canada. Wavelength-dispersive electron microprobe analyses show substantial Y and other rare-earth substitution. The mean of three spots on the diffraction-analyzed grain contains 36.37 wt% Yb2O3 and totals 95.75 wt%; a separate embedded grain contains 32.27 wt% Yb2O3 and totals 98.27 wt%. The authors attribute the low first total mainly to charging in nonconductive epoxy; this explanation was not independently established and the values are not corrected here. These are grain compositions, not ore grades or extraction yields. Powder diffraction of three grains supports a tetragonal xenotime pattern consistent with I41/amd and refined cell dimensions a = 6.866(2) and c = 6.004(3) angstrom. Suitable material for single-crystal structure refinement was unavailable. Powder intensities were estimated visually, without an internal standard or film-shrinkage correction. The reported density of 5.85 g/cm3 was calculated, not measured. Geological discussion of fluoride complexing does not establish a controlled formation, microbial extraction or recovery process. No industrial deployment or jurisdiction-specific criticality designation is asserted.

Record source: data/records/xenotime-yb.yaml