An industry initiative is known as the ASSURE Program, run jointly by the Diamond Producers Association (DPA) and Signet Jewelers to develop a universal standard to test the performance of diamond verification instruments in a consistent manner, has published the results of its testing online at the ASSURE Directory.
A diamond verification instrument is any device that is used to identify and/or separate natural diamonds from synthetic stones. The ASSURE Program initially worked with 11 manufacturers including the Gemological Institute of America (GIA), HRD Antwerp and De Beers’ International Institute of Diamond Grading & Research (IIDGR) and tested 18 of the most widely used instruments put out to the global industry by them.
The ASSURE Test Process, which was run independently by testing specialists UL, used a sample of 1,000 natural diamonds, 200 synthetic diamonds, and if applicable, 200 diamond simulants. According to the DPA, the ASSURE sample has a significantly higher proportion of synthetic diamonds that would be normal in a contaminated parcel and includes very challenging custom-made synthetic diamonds which are not commercially available for gem applications. Therefore, these results need to be interpreted in the context of that sample.
The ASSURE Core Sample contains:
Natural diamonds with a controlled type I/II distribution
HPHT synthetic diamonds and CVD synthetic diamonds, some of which have received specialised treatments during and after the growth process.
Diamond simulants including cubic zirconia, foil backed glass crystals, synthetic moissanite and colourless synthetic corundum. Only instruments claiming to be able to handle diamond simulants are tested on these samples.
The natural diamonds and diamond simulants are commercially sourced. Most of the synthetic diamonds are also commercially sourced, but some are not yet available on the market as they are currently both too difficult to produce and prohibitively costly for commercial purposes. However, they help further assess the extent to which the instruments tested are future-proof.
All stones in the ASSURE core sample are larger than 2 mm in girdle diameter, D-J colour, round brilliant cut, and mixed clarity. Results initially published in the ASSURE Directory have all been obtained with the ASSURE core sample.