[en] A program was initiated to study the potential of TL measurements for the characterization of obsidian sources from Guatemala. Research to date was intended to answer three questions: (1) Is there intra-source consistency in TL glow curves. (2) Are the glow curves from each source significantly unique to allow discrimination. (3) Can one match artifact glow curves to source glow curves in cases of known provenance. Results are in agreement with neutron activation analysis