Rubber to Ceramic

We recommend:

Household Goop

But please do a test in a small area first. It might be reactive to the rubber. If it is then try:

Hot Glue

It's less toxic but not fool proof,
glue will pull away from ceramic if tugged on.
Apply glue to ceramic piece, let cool for a few seconds, then apply rubber. Another option if glue is reactive with rubber is:

3M 80

Guaranteed not to react to rubber, but again, will pull away from ceramic if tugged on.