Okay so, I recently inherited a collection of gems and one of the pieces is a fairly large sapphire. The lawyer told me it came with a GIA report but I haven't gotten to the report yet (so much paperwork!). I don't really know the carat weight, or whether it is treated or not. The lawyer assured me it was of Kashmir origin but I know a kashmir stone is worth 3x the same Ceylon stone and 10x the same African stone. Anyways, I just want to know the best and safest way to clean it. I know corundum is scratch resistant (9 on mohs, I think) but will any chemical cleaners harm the stone? Is it safe to set in a ring? If it is indeed treated (which I think it is because it is very clean and even color, especially considering its size) do I need to be carefully not to damage the treatment?