The first three can be assessed objectively but the clarity is a more subjective assessment and hence the grade of a diamond, and therefore its value, can leave experts in disagreement. Dr Tony Holden, who specialises in improving decision making in business operations, and his team at the Department of Engineering's Institute for Manufacturing have developed a system to make the grading of diamonds and other precious stones more consistent. Tony and his colleague Matee Serearuno have developed an optimisation system called iGem that can grade stones effectively and calculate the best way to cut the stone to minimise waste.

Four diamond experts were asked to grade a set of 503 representative computer-generated stones and their opinions were then used as a set of rules for the iGem system. The model of the stone is fed into the iGem system. If a stone is borderline between two grades the system uses an Artificial Intelligence based optimisation technique to explore the different ways the stone could be cut to maximise its value, and keep waste to a minimum.

Tony is talking to Calibrated Diamonds a company based in Johannesburg, South Africa, about combining his optimisation techniques with an advanced laser cutting system. John Bond the founder of Calibrated Diamonds says that this partnership will lead to a completely automated process that will reduce waste and reduce the turnaround time from months to days.