X-rays could be used to detect some kinds of fakery. Repaired fractures would show up well, as would pigments containing heavy (opaque) metals. The process would not harm the calcium carbonate, though I suspect that it might fade the pigment somewhat (if ultraviolet light fades pigments, then X-rays might do so more effectively). Yes, film is expensive, but it might be worth it for appraising several expensive shells at once. Any comments from the radiologists among us? Andrew K. Rindsberg Geological Survey of Alabama