They are St Jude Thaddeus, patron saint of lost causes, the one looks older then the ones they produce now, but any catholic pendant usually only says Pray For Us on the back if they have anything, either way. And yes, I do realize you said they were blank on the back, I just figured I would mention that.
I kind of feel dumb, given that these two say the pray for us on the front, I just noticed, but the ones that have it on the back, it's usually accompanied by a rose, but I myself will be bidding on these when the time comes, as I do like them.