Grime-Encrusted Ring

You have uncovered what appears to be a ring from the corpse of one of the Dark Iron dwarves. It is difficult to tell what kind of ring it is, however; dirt and hardened residue cake the item completely, making wearing it impossible. You think you can make out the slight luster of precious metal and maybe even the glint of a gem under the residue. If you are going to make use of this ring, you are going to need to find something to get the hardened residue off of it.