Diamonds According to Chow Tai Fook official website's introduction, the inlaid material of the heart-impact pendant is diamond, and the diamond clarity is SI 1/ defect. Chow Tai Fook is the largest jewellery company listed in Hong Kong, specializing in Chow Tai Fook brand jewellery, jade and gold ornaments. Is a comprehensive enterprise integrating raw material procurement, production design and retail service, and is the most famous and largest jewelry brand in China.