Fossil shells that exhibit color under ultraviolet light can be identified and studied by characteristic patterns that emerge, when no color would be evident under ordinary light. Fluorescent and nonfluorescent shells may be brightened under UV light by soaking them in diluted chlorine bleach for at least 72 hours. But prolonged exposure of naturally fluorescent shells to sunlight has a stronger effect than bleaching. The melanin pigment in the shell seems to be responsible for the success of the treatment. Photographic techniques used at Tulane U. And other centers are offered, and the author suggests how the phenomena can be used for a museum exhibit.