Chemical composition, crystal structure and fluorescence properties for scallop shells have been systematically investigated with the primary objective to convert scallop shells into functional materials. Scallop shells fired at 100-500°C show a white fluorescence, and these fluorescence intensity of the sample fired at 200°C is particularly high compared to other temperature. On the other hand, when fired at 800-1100°C, the shells show a blue-white fluorescence, and the fluorescence intensity of the sample fired at 1000°C is particularly high compared to other samples. As a result of XRD measurements, it is showed that the former samples are CaCO₃, and the latter samples are Ca(OH)₂.