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