My (now) fiance purchased my engagement ring on this site. He selected a ring, with a specific clarity rating to ensure there were no visible inclusions (imperfections) in the diamond. He contacted rokstok to verify that indeed there were no visible inclusions. Not only does the website certify that specific clarity rating, but the person on rokstok's phone line personally vouched that there would be no visible inclusions. Guess what? I got my ring, and noticed within the week (while admiring it lovingly) that indeed there were noticable inclusions. Yes, rokstok does offer a 30-day guarantee, but my fiance had ordered it well in advance to make sure he had it for the "right moment". And, when I called to complain, the guy said I could send it back, but that he would basically only offer me credit for my diamond, and that my fiance would have to pick out a whole new stone, paying extra to make sure there were no visible inclusions. Even though they vouched for the specific clarity rating my fiance chose. They would not offer him the difference in refund for the lesser clarity rating which my diamond truly appeared to be. Essentially, my fiance did not get what he paid for.