Synthetic Diamonds – how to prevent mis-selling


Synthetic Diamonds – how to prevent mis-selling

By Simon Rainer


The following article was written by respected industry consultant Simon Rainer, Freeman of The Goldsmith’s Company and Founder at Simon Rainer Consulting.

April 2019 – In light of the US Federal Trade Commission’s stance against synthetic diamond growers for “misleading marketing claims” regarding product provenance, perhaps now is the time to examine some synthetic diamond equipment manufacturers’ claims of accuracy – these now reaching the public domain.

When reputational integrity is essential to any jewellery business, the consequences of mis-selling a natural diamond as a synthetic presents many threats. The accuracy of diamond screening and authentication is paramount.

A recent report relating to synthetic diamond detection instrumentation test results, is now available to those looking to understand more about synthetic diamonds and perhaps even buy their own detection equipment.

I refer to the Diamond Producers Association’s (DPA) Project ASSURE report that independently tested the accuracy of 11 detection units from 7 manufacturers and also offers very useful advice on supply chain protocols.

Before I get into the results themselves, it is important to know the difference between synthetic diamond screening and authentication.

Authentication instruments determine the nature of each specific stone. Screening instruments verify the vast majority of natural diamonds but refer the remaining natural diamonds for further testing – along with any synthetic diamonds.

(It is worth remembering that a natural IIa diamond and CVD synthetic will both be referred as they share the same properties of low to zero nitrogen content.)

Diamond laboratories such as those managed by De Beers Group Industry Services and the Birmingham Assay Office are two UK facilities offering authentication services for stones that have been referred for further testing.

Of the instruments tested, all had screening capabilities, but only one was capable of authentication; the De Beers Diamond View.

Before you invest in any synthetic diamond detection equipment, there are several factors to consider:

•     Do you need to test loose stones or mounted? or both?

•    Volume of stones to be tested?

•    Do you need to test melee?

•    What is your budget?

•    Do you want the unit to also detect simulants such as CZ or Moissanite?

•    What is the experience of the in-house operator?

•    What size of stones are to be tested?

•    How portable do you need the unit to be?

•    What accuracy are you happy to accept?

Diamond accuracy as defined by the DPA is: – “the ratio of diamonds correctly classified as diamonds to the total number of diamonds”

DPA Project ASSURE results:

•      De Beers Diamond View – 100%

•      De Beers SynthDetect – 99.3%

–   De Beers AMS2 – 99.1%

–   NGTC GV5000 – 98.5%

–   Yehuda Sherlock Holmes – 97.5%

–   Taidam Diamond Dect 3 – 96.4%

–    HRD M-Screen+ – 95.9%

–    De Beers Diamond Sure – 95.3%

–   Taidam Diamond Dect 5 – 91.6%

•     GIA iD100 – 89.9%

•     Presidium SDSII – 84.5%

The full DPA report can be found at and will help you work through all your buying considerations, in addition to providing full reports on all the equipment listed above. In the UK, Birmingham Assay Office, De Beers Group Services and the NAJ are leading the way in providing professional advice and education services for all those looking to understand more about the increasingly complex world of synthetic diamonds.

Synthetic Diamonds – how to prevent mis-sellingDe Beers Group Industry Services