'Mani in Fede' - Hands in Faith

While reading the obituary of Frank McCourt, Irish American author of Angela's Ashes, I learned that his brother wrote a book about the Claddagh ring and realized that these rings have an ancient origin.

The Claddagh ring belongs to a widespread group of finger rings called “Fede Rings”. The name "fede" comes from the Italian phrase mani in fede ("hands in trust" or "hands in faith"). These rings date from Roman times, when the gesture of clasped right hands (dextrarum iunctio) symbolized marriage. Fede rings are distinguished by having the bezel cut or cast in the form of two clasped hands, symbolizing faith, trust or “plighted troth.” They were popular in the Middle Ages throughout Europe, and there are examples from this time in the National Museum of Ireland, Kildare Street, Dublin. (Wikipedia)

Another source provides this information:

A handshake symbol on a tombstone usually signifies a welcome into the heavenly world. Sometimes you may see this as a symbol of matrimony on the grave marker of a married couple. If it’s a marriage symbol you may notice that one cuff will look masculine and the other, feminine. (http://cemeteries.wordpress.com/2008/05/06/handshake/)