Morning everybody, and thank you as always for your help. I was Setting a large piece of onyx in a cuff, and one of the components popped off. So I took a chance and covered the stone and the other components with Rios cool gel. I piled it on. I just soldered the component back on, Stopping to add more Rio cooling gel, as I see it sort of bubbling. I was left with a thin film that looks like hard water scale on part of the Onyx. I tried scraping it off with a X-Acto knife I tried polishing it with a compound with grit in it, I tried running a radical disc over it. Nothing helped. I soaked it overnight in a mixture of vinegar and baking soda. I’m probably delusional but it looked like a little bit came off. Anybody have any other ideas how we can remove this, maybe burnt cooling gel off the stone?