Chow Tai Fook not only has the certificate of national testing, but also has its own testing organization. There are many kinds of certificates, including national inspection, international inspection and provincial inspection, and they are also divided into second-hand goods and new goods. Like Chow Tai Fook, diamonds over one carat will be issued with GIA international inspection certificate, but many diamonds with smaller scores will not be issued with GIA international inspection certificate, because the cost is relatively high, which is several times worse than the domestic certificate. Most of them are national testing certificates now, but don't worry.