Graptopetalum of some kind. Thought it was paraguayense, but I am thinking not.
It’s really beautiful, but I hope it’s rooted well and will stay healthy. Need to repot it (and two more in the same type of pot) into vessels with holes that will drain. Haven’t watered this one yet, but will only do so extremely sparingly until I get it into something that will drain and breathe better, which is too bad because the white pot is quite nice looking.