Hongkong local, Chow Tai Fook, Zhou Shengsheng, Lukfook Jewelry, TSL Xie Ruilin, Golden Supreme, Jingfu, Jinliufu Jewelry, Yijin (Zhenjindian), famous diamond shops and so on. I recommend you to go to the first three, which is more reliable. (Note that Leofoo is from the Mainland and has nothing to do with Lukfook Jewelry in Hong Kong. There is no Leofoo in Hongkong. )

Cartier, Van Cleef & Arpels, Tiffany and I won't talk about it. They are all international brands anyway.