I looked at them when I got home and they look very nice. I can see one that many have a small piece of carbon in it but it would still be no worse than a SI grade. I think the ring may be almost new since she had it in a ring box. She was only in her early twenties so I know it not very old. For those of you who don't know a platinum ring is marked "PLAT" instead of 14K. I do know a little about jewelry but I am not an expert. Twenty years ago I had a small spot in an antique mall. I figured in order to be able to buy jewelry I needed to have an idea of what various stones were worth so I wrote to a company that publishes the jewelers diamond and colored stone price guide. They sent me a sample copy that was a few months out of date. It shows the price for every size and grade of diamond. It was so neat that I still have it. I also just got a new diamond detector for Christmas last year and I used it today for the first time. I carry it in my car along with a portable Gram scale just in case.