**3. Autofluorescent crystalline silica detected by using a LSCM**

Autofluorescence characteristics of minerals have been described by Henkel (1989). In this chapter, we document the visualization and identification of chalcedony crystals in electric organs, by using a Leica TCS - SP2 Laser Scanning Confocal Microscope (LSCM). This microscope has three ion lasers i.e.: argon with emission band in 458 nm (cyan), 476 nm (blue-green), 488 nm (green) and 514 nm (yellow); He/Ne with emission band in 543 nm (red) and He/Ne with emission band in 633 nm (blue). Since chalcedony is characteristically an autofluorescent mineral, we were allowed to obtain images of crystals.
