To investigate the detection of irradiated shellfish, seven kinds of shellfish samples were gamma irradiated at 3 and 6kGy. The first-glow curves for all the control and irradiated shellfish samples were recorded between temperatures of 50 and 400°C at a heating rate of 5°C/s. All the samples, the first glow curves (TL 1 ) of which have been recorded, were re-irradiated at 1kGy for the normalization of results. Their second glow curves (TL 2 ) were obtained at the same conditions in order to achieve the thermoluminescence (TL) ratios (TL 1 /TL 2 ). The TL method proactively identified the whole shellfish samples by using the calcite, aragonite and quartz minerals that are present in the shells. The X-ray diffraction spectroscopy has been used as an analytical tool for the characterization of minerals that are present in the shells as inorganic materials along with biomaterial.