I would have thought cubic zirconia are hard enough that you can use polishing wheels and papers meant for soft metals without worrying about the cubic zirconia being scratched. I think they are 8-8.5 hardness. I’ve been purchasing CZ’s from cool tools and firing them in place. I notice that on polishing they get dulled and scratched. I use some cheapo “scrub” wheels I get from Amazon and 3M polishing papers. Does this sound normal that they can be scratched? If so, how should I handle that? I was thinking maybe cover them with some painters tape or something.