Luminescence of uranium and rare-earth elements in apatite of fossil fish teeth

Time-delayed laser-induced luminescence of uranium and rare-earth elements (REE) in apatite of fossil fish teeth from the phosphorites of the Senonian Mishash Formation, Israel, were investigated before and after thermal treatment. heated samples show luminescence of UO2+2. Luminescence of REE3+ (Sm, Eu, Pr) is observed only after heating the samples at 1100 K in air. The spectral properties indicate that UO2+2 in the unheated samples is located in two different positions, as aqua-complexes of uranyl-ions and associated with organic matter. The REE in the unheated samples are accommodated in non-luminescent form. After heating the REE3+ (Sm, Eu, Pr) are located in the Ca2+ II site presumably due to thermal diffusion.