A two-part journey to the heart of Asia to uncover the exotic history of the imperial green jade, the world's most valuable gemstone. In this first programme journalists Adrian Levy and Cathy Scott-Clark visit the opulent auction rooms of Hong Kong where today's dealers fight over the best pieces of jade, fuelling an obsession which has its roots in ancient Chinese tradition. Readers Daphne Cheung , Crawford Logan and Ozzie Yue. Producer Amanda Hargreaves