A novel optically based diagnostic for urinary stone identification is described. The concept is based upon the well founded and sensitive technique of laser induced fluorescence (LIF). The Phase I project will determine in vitro, using several commonly found stones, whether LIF can be used to identify the composition of the stone. The photoemission spectrum observed will be recorded for several types of stones. Characteristic spectral signatures will be sought for each type. If the stones indeed shown characteristic features then one can identify unknown samples by these spectral signatures. This could lead to a new clinical device for stone classification, and, perhaps more more importantly, a minimally invasive, fiberoptic based device for in-situ identification prior to treatment.