West Coast Diamond Club Special Lecture And Workshop On Synthetic Diamonds
Forty participants from the West Coast Diamond Club, Inc. (WCDC) had a chance to participate at a special lecture and workshop on synthetic diamonds presented by AGS Conclave attendee, Branko Deljanin of CGL-GRS Lab of Vancouver, Canada.
The lecture was designed for wholesalers, dealers, jewelry sales people, gemologists and appraisers to ‘at their desk’ identify some of the characteristics of synthetic diamonds, the WCDC said.
The title of the lecture was, Identifying Synthetic Diamonds with Portable Instruments (Loupe, UV lamp and Polarioscope). In the two-hour workshop the participants learned to screen for type II diamonds (that could be natural color, HPHT enhanced, HPHT-grown and CVD-grown) and identify HPHT synthetic diamonds with portable instruments by using a portable polarioscope and the new “PL inspector”. This instrument comes with a guide on “Diamond Fluorescence as a Tool for Diamond Identification along with photos of natural, treated and synthetic diamonds under LW and SW UV light for reference.
In some rare cases CVD-grown diamonds that do not fluoresce and have strain pattern similar to natural type IIa will need to be sent to an advanced lab for further testing to confirm synthetic origin, Deljanin explained.
He also said that the vast majority of synthetic diamonds on the market today are SI1 or higher clarity and even with a 10 x magnification or microscope it is not always possible to distinguish these stones from natural diamonds.
Participants learned that most large and melee synthetic diamonds are produced by HPHT (High Pressure High Temperature) process. And even though historically in high colors most dealers do not like to see blue fluorescence in diamonds. Medium, strong and very strong blue fluorescence is generally a positive indicator of a natural diamond.
Deljanin said he has never observed high fluorescence in synthetic diamonds during his 22 year career working in, and now owning, a diamond grading laboratory.
Kalpesh Jhaveri and Mervyn Haan, co-vice presidents of the DCWC and attendees at the seminar, said, "This was a very informative presentation. Branko Deljanin is an authority and well versed in the subject.
"Presentations and seminars of this nature help to empower our members. We look forward to bringing many more such distinguished speakers to DCWC in the future."