MEMBERS: PART TWO: Delicious coloured diamonds, can you tell if they are natural, synthetic or treated?

PART TWO: Delicious coloured diamonds, can you tell if they are natural, synthetic or treated? Do you need expensive gear to identify them? How can a regular Gemmologist identify them if I don’t have a lab?

COST: FREE (member only event)

BOOKINGS: Limited spaces – advanced registration required. Contact Kathryn Wyatt with any issues: publicity@gem.org.au or phone 0412 195 964.

The presentation will cover diamonds coloured yellow/orange, blue/violet, pink/red and green and include a visit to chameleon and white diamonds. In the presentations, John will explore the nature of the defects responsible for the colours and how they differ between natural, lab-grown and treated diamonds. These defects may include nitrogen in various forms, voids, boron, hydrogen and other elements.

Techniques to detect colour origin are based on fluorescence, birefringence, photoluminescence and absorption spectroscopy (vis and IR). John will present an overview of these techniques and how they can be applied to coloured diamonds to understand the origin of their colour better.

Who is John Chapman?

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. In the past few years, he has been director of Gemetrix Pty which has developed and currently manufactures luminescence-based instruments to detect synthetic and treated diamonds, more recently adding a spectrometer to the company’s range. When not designing and manufacturing the devices, John directs his experiences and knowledge into Delta Diamond Laboratory that specialises in verifying the origin of pink diamonds from Argyle. John is also chief editor for the Mediterranean Gemmological and Jewellery Conferences.