Oh, you can get the onyx wet to clean it, just do not soak it in water. So cleaning onyx and diamond ring you should be a bit more careful but you can still use a soft brush, wet it and clean the diamonds with it (its ok if you touch the onyx as well as long as you do not really soak the onyx in water you will be fine). After you are done cleaning the ring please don't forget to dry it with soft dry cloth.