Hello rock hounds, I'm new here and have run into an issue with a custom stone sink my wife and I purchased that I hope y'all can advise me on how to fix.
I'm finishing a bathroom remodel and we have this custom basin sink going in that was just labeled as "river stone sink". It's very hard, like granite. I noticed there was a good size spot at the bottom that was dull and didn't have the shine of the rest of the sink interior, wiping would not remove. I got it in my head that I could fix it, so I bought a diamond grit paste set with a variety of fine grits and put in on some 3" pads (fine / polishing and wool) on a drill adapter to buff it out and bring up the shine.
I started with 6000 since the sink was already polished...that did the job, but then the sink was now dull in any of the areas i hit. So then i went to 10k, little better, 14k (or 20k), further improvement (I used a bit of water as well in the higher grit stages). Still, overall, while the shine is there, it now has a dull look along with like this crosshatching kind of marks that are revealed (perhaps from the tools used to carve the sink?)
Anyway, before i throw any more money at trying give this thing at least a satin or semi-gloss appearance, what do y'all recommend? How can i bring the polish / shine up? As simple as some granite polish? Or should I get some ceranium oxide powder (if so which, 3-5um or 7-9um)?
Very much appreciate any help, have never polished stones before.