In 1960, he founded the Graff Diamonds company. In 1966 he commissioned the English jewellery-designer Robert Thomas to design a Diamond jewel to enter into the De Beers Diamond International Awards competition. The ribbon bracelet created won the competition. By 1974, he had begun specialising in selling to newly rich buyers from the Middle East. In particular, he supplied many jewels for Hassanal Bolkiah, the 29th Sultan of Brunei, who became a lifelong client and friend. One day, Prince Turki II bin Abdulaziz Al Saud walked into the shop and bought everything including a 14 carat Diamond. Graff has expanded his company, with over 35 stores in US, Europe, Asia, Africa and the Middle East.