Free-standing, 8 nm diameter, rare-earth doped nanoparticles Re10Pb25F65 have been prepared, where Re stands for either single rare-earth ion, such as Er3+, Yb3+, Eu3+, Dy3+, Ho3+, Tm3+ or combinations of those ions. The nanoparticles have been extracted by chemical etching from the oxyfluoride nano-glass-ceramics template and analyzed by transmission electron microscope with energy dispersion spectroscopy. The nanoparticles show durable up-conversion photoluminescence, which is neither concentration nor impurity quenched after 6 months ageing in ambient atmosphere. High doping levels in these nanoparticles ensure high, up to 15%, quantum yield of up-conversion luminescence. (c) 2008 Optical Society of America.