John Chapman has a degree in physics and has been active in the diamond industry for over 30 years with technical roles across the diamond pipeline from exploration to diamond grading. John has worked for Rio Tinto Diamonds for much of his career where he had a special interest in pink diamonds and initiated three PhD studies into the colored stones. He also developed machines for classifying rough diamonds and an instrument for color grading pink polished diamonds. In the past few years he has been director of Gemetrix Pty Ltd. which has developed and currently manufactures luminescence-based instruments to detect synthetic and treated diamonds. Besides also providing technical consulting services to the industry, he is chief editor for the Mediterranean Gemmological and Jewellery Conferences. John lives in Perth, Australia.