In the platinum ornaments marked YBD, some products are doped with 6% ~ 10% iridium. Platinum is much more expensive than metal iridium, and their smoothness and brightness are similar, which can not be distinguished not only by naked eyes, but also by many small X-ray fluorescent gold detectors. Some "black-hearted" manufacturers use this loophole to put iridium-doped platinum jewelry on the market.