A CALL FOR HELP FROM A KOVELS READER

This is a reverse tip. Can anyone help with this email request? We have never heard of this problem. "My sister has a huge Roseville pottery collection. She has noticed small chips of paint on her shelves and determined that something is 'eating' her pottery. She said there are tiny holes that are suddenly appearing and hairline cracks in the pots." She goes on to explain that this has happened only since her sister moved to a new house. We suspect there was an abrupt change in the moisture level surrounding the collection, but properly fired pottery should not be affected this seriously. Suggestions are welcome.