I’ve had my father’s ring for 22 years, without a stone. In fact I remember this ring from the mid ‘70 and the stone was missing even back then.
I recently had a small, pale blue-gray star sapphire that I’ve had for years (I’ve collected cut gemstones for decades) mounted by my jeweler and he did a great job. But because he needed to alter the prongs to accommodate a cabochon stone, the ring is polished and very shiny. It had a very rich patina from decades of use and storage, which I’d like to at least replicate just a little.
Sapphire is technically corundum which, according to the University of Waterloo’s Earth Sciences Museum website, is “unaffected by acids and most environments” so I don’t believe any chemicals that might work would harm the stone. But I do have a couple extra small sapphires that aren’t gem quality I could test first.
I’ve tried google searches but can only find how to remove tarnish, not replace it.
I don’t want to ask my jeweler because I don’t want him to feel bad for polishing it, but as a last resort I can ask.