One potential option that Anonymous might want to look into is a third class relic. This is oftentimes a piece of cloth touched to a first or second class relic, and sometimes included in holy cards for a saint. I have one for St. Joan. It may or may not be easy to find a third class relic of a pre-1054 saint, but I'm guessing some can be found. The commenter who mentioned having a piece of stone from a cave where St. Michael appeared has what many trad Catholics would consider a relic of the archangel (though officially, I don't think it is considered so).