Simon Taylor writes,
"I recently bought an old collection and many of the shells were varnished.
I have tried any number of ways to take it off and have met with limited
success. Proprietary varnish remover (intended for furniture, etc) will get
it off but goes very gloopy, especially when you wash it off. This is a
nightmare with shells which have detailed sculpture and/or fine spines."

It never ceases to amaze me what people will put on their shells. Rixon's
"Fossil Animal Remains" contains many tests for such chemicals and advice on
how to remove them. Most shells need no special chemical treatments, much
less varnish, nail polish, shellac, ... but I can't go on. I have to save my
strength to deal with a small horde of visiting 10- and 11-year-olds in a
few minutes. Simon, you have my sympathy.

Andrew K. Rindsberg
Geological Survey of Alabama