it's a ring of appraisal and would be useful, but you never get to equip it and if you get it appraised in the mage guild you kinda.. never see it again. mostly take this route if you really feel fornicating with rats is icky I guess.
same for the riddle reward. feels cool to be right and solve it and the ring has windcutter or something, but again, you never even get to equip it, and the mage appraiser never gets it back to you. (to be fair, not like he has much chance for that)