these little religious charms have been made for many years and the style doesn't change that much. if they are silver and are hallmarked, they can be dated to some degree. if they are not hallmarked (i can't see any marks on yours) you have to judge age by patina, wear, construction, etc. i would guess yours is anywhere from the 30s to the 60s or so.
ricordo means "i remember" in italian, this may have originally hung off a bracelet.