I stopped in at a Zales to see if they could clean or give me options on what to do with my (not natural) black diamond. They tried to clean it but couldn't get the surface gunk off of it. I went down the way to Fast Fix and in less than 5 mins they had completely cleaned it off and had it shining once again. I would definitely recommend this place to anyone looking for a wide variety of services for their jewelry. If I need anything else I will be going back there.