Taggants are synthesized fluorescent materials that have longer lifetime and are able to discriminate against background interference arising from hydrocarbons. Doped taggants were prepared with dysprosium and terbium rare earths in a stable borosilicate and tellurite glass host. The composition of the doped borosilicate glass were (60-x) ZnO + 20B₂O₃ + 20SiO₂ + xLa³⁺ (where La³⁺ = Tb and Dy), while the composition of doped tellurite glass composition was (80-x) TeO₂ + 20LiCO₃ + xLa³⁺ (where La³⁺ = Tb and Dy) with values of x corresponding to mol% increase from 0.5, 1.0, 1.5, and 2.0 and subsequent decrease of ZnO and TeO2 composition. The fluorescence emissions of dysprosium doped borosilicate and tellurite glass was 574 nm while Terbium doped borosilicate and tellurite glasses at 544 nm. The UV/Vis absorption characterization showed dysprosium doped borosilicate glass as having the strongest absorption spectra with several excitation peaks and maximum absorption (λmax) at 350 nm while fluorescence compatibility test for cyclohexane and crude oil identified Dysprosium borosilicate glass and terbium tellurite glass as the optimum taggants showing compatibility with the hydrocarbons.