Nirav Modi. Indian-born diamond jewellery designer Nirav Modi is the founder of the $1.8 billion (revenues) Firestar Diamond, which makes diamond jewelry for exports. In recent years he has been expanding the retail presence of his Nirav Modi brand with eight stores in locations such as Delhi, New York, Mumbai, Hong Kong, London and Macau. He recently appointed Bollywood actor Priyanka Chopra as brand ambassador and says he plans to open 10 more stores.