Great! This is what I was hoping to hear and am happy to know I was correct on my thoughts about the grade. Interesting on the fact that it may have been cleaned as it is a family piece passed down so we known who had it at all times and I certainly never had it cleaned nor cleaned it myself. My grandmother kept it in her jewelry box her whole life and said it was something her mother did the same with. It was originally in a necklace mount so maybe it was cleaned then. Thanks again!