Undisclosed Yellow Lab-Grown Melee?


An interesting item in last week’s GIA Insider indicates there may be more undisclosed synthetic (yellow) diamonds out there than previously thought.


According to the report, The Gemmological Association of All Japan’s Zenhokyo Laboratory recently examined 870 pieces of yellow melee over four months.  It turned out that ten percent of that loose melee – 85 stones – was lab-created.

The lab also looked at 30 pieces of jewelry set with yellow melee – and found that at least half the pieces had lab-grown diamonds mixed with natural stones. Pretty significant — and a little unsettling.


The good news is, this isn’t a scare item (totally). The Japanese researchers have apparently discovered a method that could help detect synthetics in batches of melee or when they are mounted.  The method – “Micro-FTIR” (Fourier-transform infared microspectroscopy) – has been used in other fields, and could be a breakthrough in detection of lab-grown melee.


One word of caution: this technology isn’t the mythical “black box,” but something that requires a technician to interpret the data. 

For those of you more technically-minded folk, there will be an article about all this in the Fall Gems and Gemology.  It will be interesting if other labs start using this technology. But sure seems promising.

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JCK News Director

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