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The machinery and equipment suppliers have developedand now market a variety of instruments that purport-edly screen and identify both treated and lab grown di-

amonds. The capabilities of these instruments vary. The rangeof pricing is from a few hundred dollars up to about $10,000,while more advanced levels for testing utilized in the labora-tory setting can go well over $100,000. Besides the use ofthese screeners/testers, some major laboratories are nowalso offering low cost batch testing as a service.

One of the concerns that we have is that the jewelry industryis being led to believe that these instruments do more thanthey actually do. They are definitely useful tools but they arenot the end-all “black box” solution that everyone would like.They are most often marketed as diamond testers when infact, most of these are actually screeners that offer resultsthat include “natural” or “refer for further testing.” The refercategory may be natural, treated, or lab-grown. These instru-ments are screening for TYPE IIa diamonds which can be anyof the latter three choices. Whether a screener or a tester,these instruments come with limitations. They do not do itall and they do not have total accuracy. That is important tounderstand because while we believe that there is good rea-son for many industry businesses to own a screener/tester,you must know the limitations and accuracy level.

There are some areas to discuss here. What are the actualuses of these screeners/testers and what do they test for?What considerations should be made in deciding on a pur-chase? What is the practical use for the jewelry manufacturer,the retail jeweler and the appraiser? It is important to notethat this article cannot possibly cover all of the instrumentsavailable. It is also possible that some have undergone someproduct changes since last researched. Pricing, when given,is as we know it but may also have changed. You should re-search as many instruments as possible before making yourdecision to buy. We are not recommending one over another.

PRACTICAL USE FOR THE MANUFACTURERWorking for Canada’s largest jewelry manufacturing company(JP), our very real problem both past and present is withsmall synthetic melee that are salted into natural parcels.

Specifically, the undisclosed lab grown diamonds, now com-monly referred to as LGDs, cause the most concern to usand all diamond manufacturers.

While our jewelry line uses Canadian sourced diamonds forthe larger stones, melee is still outsourced for practical(economic) reasons. Most jewelry manufacturers therefore,buy parcels of melee on the open market, in our case,mainly from India. India is one of the main centers whereLGDs proliferate in natural diamond parcels. They are usu-ally purchased from China producers for dollars per carat

so even a small percentage salted into a natural diamondparcel of 10,000 stones can be profitable. What can alsohappen is that the dealers will supplement parcels from asecond supplier without screening to fill an order and with-out telling the original buyer.

For absolute certainty, jewelry manufacturers may stillchoose to do further screening beyond the guarantees of thesupplier. With the potential fines and damaged reputationsand loss of customers, full secondary testing may be pru-dent. One method is to send the diamond parcels to otherindependent laboratories for melee screening services. Thishas been touted as a low-cost option that some jewelry man-ufacturers have opted to do. Others like the company that I

DIAMOND SCREENERS/TESTERS

Richard B. Drucker, GIA GG, Honorary FGAJon C. Phillips, GIA GG, AGS CG

The jewelry industry has a real concern for the impact of lab grown and treated diamonds. Selling justone, even if unknowing, can be damaging to that seller’s reputation and potentially a legal issue. The con-cern is among manufacturers, retailers, and appraisers. We examined several of the instruments on themarket looking at their practicality from the various aspects of the industry.

FEATURE ARTICLE

When jewelry such as this is being sold, do you know for sure that all ofthese are natural untreated diamonds? Will an instrument insure that theyare? Image courtesy of Corona Jewellery Company.

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work for may opt to buy their own equipment for testing. Thecompany now requests the suppliers to screen and then wescreen, hence a double screen process. The point of this isthat even with the so-called “guarantees” by suppliers, onemust approach this issue in a way that it’s a given that thereis likely LGDs in the parcels of natural melee purchased. Itonly takes one LGD and a visit from a news agency to ruinyour whole business. And those penalties to a manufacturercan be up to $5,000 for just one single stone.

CHOOSING THE RIGHT SCREENER OR TESTER FOR THE MANUFACTURERThe first step is to determine what size will need screening.For our company it was as small as a quarter point up to .03ct. Will you be needing screening or identification? There is adifference. The screener kicks out potential LGDs; the identi-fier identifies the product for what it is. Next is to decide ifyou need a machine that does fast screening of many smalldiamonds or a slower single stone method. And while man-ufacturers are likely to screen loose diamonds prior to setting,they may also want to consider analyzing inventory of alreadymounted diamonds that never were screened previously.

There are many types of machines and each machine hasit strong points and weak points. In my research, I discov-ered that no current model available can be both fast forsmall melee and work individually for mounted diamonds.While many exist, for manufacturing companies, the bestchoices (for our needs which may differ for others) are de-scribed here. Each was studied thoroughly or when possi-ble, actually tested.

The five considered were DFI-MIDUV Laser from GGTL; M-ScreenPlus™ from HRD; AMS2 fromIIDGR/DeBeers; J-Secure fromDRC Techno; and DiaTrue™ fromOGI. Prices ranged from about$150,000 on the high end to$5,000 on the low end.

The DFI-MID offers definitive re-sults on loose or mounted dia-monds as natural, synthetic, orimitation. It is also used for othergem varieties. As results are defin-itive, this actually falls under theadvanced instrument category be-yond the full scope of this articleas there are other advanced instru-ments used by laboratories. Thecost is also a factor at this level atabout $150,000.

M-Screen Plus™ is designed toscreen round brilliant melee athigh speed. Depending on the

size it can screen up to 15,000 stones per hour. It is goodon D-J color range. The cost is about $90,000.

The DeBeers melee screener is the AMS2, designed forspeed and 10x faster than an earlier model. Up to 500 caratscan be tested at once and can do up to 3,600 loose stonesper hour—colorless to near colorless. Results are Pass, Syn-thetic, Refer, and Non-Diamond. The cost of the AMS2 is$45,000. Figure 1.

J-Secure is a series of instruments at different price points,also high-end. They identify CVD and HPHT lab grown dia-monds in loose and mounted. The J-series sells for $21,000to $25,000 and they have lower series models as well.

The DiaTrue™ works on both mounted and loose singlestones. It detects CVD and HPHT grown diamonds andmoissanite. However, they do note on their website thatwhile this is quick and convenient testing, a certified lab isneeded to confirm results so this does act as a very sophis-ticated screener. The cost for this instrument is $10,000.Figure 2.

One thing to keep in mind is that technology for testing equip-ment is rapidly improving. Machines continue to becomefaster, with more defined results and possibly at a lower cost.The AMS2 for example was $85,000 just four years ago, now$45,000. Co-author Richard Drucker had purchased the Dia-mondSure from DeBeers DTC back in 2005 for a specificGemworld diamond project at a cost of $10,000. Today, halfthat price will buy a similar device. And his DiamondSure

FIGURE 2. DiaTrue™ diamond screener. Photo by JonPhillips.

FIGURE 1. The AMS2 with the sorter on top wheremelee is dropped into the machine and the sortingbins below. Photo by Jon Phillips.

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stopped working several years later and the DTC said it wasunrepairable as it was older generation equipment.

One of the main issues that arose early in our search andshould be a consideration in yours as well is that we hadto establish what we needed to determine. Did we wantto identify LGDs by gemological standards or did we justwant to detect and screen out the potential LGDs? Thegemologist side wants to know for example if it wasHPHT, CVD, HPHT on CVD and if it was natural then whattype. But considering the amount of time needed to bespent on each 1mm stone, manufacturers will likely optto go for speed and detect only, not identify. In our case,it was ultimately decided that we needed one machinethat would catch and reject loose CVD, HPHT and conceiv-ably CVD with an HPHT treatment, although I have notheard of CVD with an HPHT treatment on very small col-orless LGDs. This narrowed the selection of availableequipment. In our decision, we decided on two machines,double screening, and to just reject any that still came upas refer regardless of reason.

PRACTICAL USE FOR THE RETAILER AND APPRAISERWith the prevalence of lab grown and treated diamonds inthe market, jewelers and appraisers have been on edgeabout detection, liability, and value of these diamonds. Cur-rently, the gemological laboratory community is confidentthat all man-made diamonds are identifiable with testing.GIA routinely screens diamonds submitted to the lab as partof the report process. The categories are distinctly different.There are large diamonds either loose or mounted and thereis melee. Starting with larger diamonds, most of thesetoday are sold with a laboratory report. When this is thecase, generally there is no concern or problem. Note how-ever, that there have been instances where someone hassubstituted the actual diamond from the report with a labgrown or treated diamond. (www.gia.edu/gems-gemology/gems-gemology/fall-2017-labnotes-synthetic-dia-mond-fraudulent) So, the jeweler or appraiser must stillconfirm that the diamond matches the report. In mostcases, loose or mounted does not create any problems,though some mountings may make it difficult to get exactmeasurements or see a laser inscription if it exists, or easilyidentify via inclusions, especially for high clarity grades.

The issue with larger diamonds is when a laboratory reportdoes not exist and this might often be the case on estatejewelry, not so much with new. Here is the need for com-fort level of confidence. Based on the diamond character-istics that you see, are you confident that the diamond isnatural? Are you using one of the screeners or testers anddoes that confirm your conclusion? If the answer is yes,then the retailer can sell the diamond as natural or the ap-praiser can value it as such. If there is any doubt, the rec-ommendation is to send it to a reputable laboratory firstbefore buying, selling, or appraising.

Today, many smaller diamonds are even sent for reports.Some as small as a quarter carat will have reports but stillmost this size will not, so before we sell or value these dia-monds, the same questions above for larger diamondsshould be asked. This gets even trickier with items like tennisbracelets with many diamonds in this size range. If the retailjeweler is buying diamonds and diamond jewelry from sup-pliers, then the supplier should be guaranteeing that their di-amonds are natural. However, even this comes with acaution. While we are not attorneys and cannot offer any legaladvice, just consider this. At least in the US, commercial codethat covers retail selling puts the liability on the seller to knowthe product they are selling. It may not be a defense to saythat the supplier “told you” the diamonds were all natural.Again, this is only a suggestion and not legal advice and dif-ferent laws can vary in different jurisdictions.

The responsibility of an appraiser differs from that of the retailjeweler that sold the item in that they are only offering an ex-pert opinion. Now, the question becomes how much they areexpected to know as an expert. Many appraisers use state-ments known as limiting conditions that are included as part

of their appraisals. One of those limiting conditions is gradingand inspection of mounted diamonds. The appraiser is not ex-pected to remove diamonds to weigh them for example, norare they expected to be exact on color or clarity due to limi-tations when the diamond is set and the subjective nature ofcolor and clarity grading. It is unclear just how much expertisewill be expected regarding the ability to identify treated andlab grown diamonds by the appraiser. They are not the seller.They are offering a post-sale opinion. Per above, even ascreener will not always give a definitive answer and mostcannot afford or financially justify spending the thousands ofdollars that might be necessary for advanced equipment.They still must provide reasonable care in how they performand are still responsible for what they ultimately write in theappraisal. As an appraiser, you should still be ready to explain

FIGURE 3.The GIA id100. Image by GIA.

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the difficulties of some exact identifications and recommendsending the diamond(s) to a reputable laboratory for testing.

The melee issue has already been covered in detail and theretailer and appraiser will have difficulty with these for iden-tifying for the reasons already covered. Again, as a retailer,you are expected to be selling natural diamonds if that iswhat you have stated. There basically is no room for toleranceif that is your representation. Some retailers have nowstarted to use language on sales receipts that explain theslight possibility of lab grown or treated occurring undis-closed or undetected in an item of jewelry.

CHOOSING THE RIGHT SCREENER OR TESTER FOR THE RETAILER AND APPRAISERWith the background information given regarding the role ofretailers and appraisers, the decision-making process for buy-ing a diamond screener or tester is likely to be different thanthe manufacturer. Here, the decision usually will focus on thelower priced instruments up to probably $5,000, thoughsome may opt to spend more. Again, knowing the need willhelp determine the choice of what to buy.

On the higher side of the price scale is the GIA iD100™which sells for $5,000. Figure 3. This instrument is for looseor mounted and is one of the easier to use. The probe issimply touched to the diamond and a reading is returnedas pass or refer. It is screening for synthetic or HPHTtreated diamonds but will require further testing to confirmnatural, treated, or lab grown for those that are not con-firmed as diamond from the probe.

The Sherlock Holmes is actually an ingenious design thatinvolves believe it or not, a cell phone permanently

mounted in a viewing box and an app built in. It tests looseor mounted for CVD or HPHT grown diamonds and is veryaccurate but it will identify a natural but treated diamondas natural, less of a concern with melee. The cost of this isalso $5,000. Figure 4.

The D-Screen by HRD is a portable screener that is screeningfor HPHT lab grown or treated diamonds. The cost of this de-vice is $3,600.

There are some lower cost screeners also on the markettoday that start at about $500. They include the GemlogisLEO UV+IR Diamond Segregator, the Synthetic DiamondScreener II by Presidium, and others.

OTHER CONSIDERATIONSBefore buying a screener or tester, whether manufacturer,retailer, or appraiser, here are a few considerations:

• Do you understand how the instrument works (screens TYPE IIa or uses spectroscopy)

• What is the accuracy rate (research this)

• What is its best use and its limitations (speed, size, mounted, loose, etc.)

• Warranty and service contracts (some companies have hefty service contracts)

• Ease of use—gemologist or non—and is training avail-able (if relevant on advanced)

CONCLUSIONThe key to screeners and testers is knowing fully what eachis capable of doing. Know how to operate and interpret theresults. Know how to care for and calibrate the device. Howeasy are they to use? Are they good with loose only ormounted? What is the accuracy level of the tests? To knowwhat a machine does, ask the right questions and if neces-sary, ask to read the manual first to see what the test resultsshow, how easy it appears to be in its use, and what the lim-itations are. Ideally, it would be great if you could get a trialperiod to test stones. At a trade show, you will be shown the“sure things,” that validate the device. The tests are set upto impress you. Bring your own difficult mounts for testing.

Note that most of the machines marketed at some point willbe stated to be a diamond tester. We believe that they shouldbe called screeners for all the reasons given. However, somelike the Sherlock Holmes do test but even these may havelimitations and exceptions.

And finally, the one issue that we have stated since thesemachines became available and that is the difficulty of whatto do when the machine says “refer.” Remember that mostmachines are screeners and when the result is refer, thenwhat? For a larger diamond the answer may simply be to

FIGURE 4.The Sherlock Holmes CVD and HPHT detector. Image by Yehuda.

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send it to a laboratory for further testing. But what aboutmelee already set in jewelry—the ring that has 20 diamondsand one or two small diamonds are screened with “refer” re-sults. It is either natural, treated, lab grown, or even a simu-lant. You cannot take the diamond out nor would it bepractical or worthwhile to remove a melee sized diamond.So, what do you say to the customer? If you are an appraiserand you now inform the client that they “might have a labgrown diamond in the ring,” what is the next step? They runback to the jeweler accusing them of putting a lab grown di-amond in the ring. The jeweler then goes back to the ap-praiser who has caused this problem. We already know of astory of a jeweler that confronted a manufacturer becausehis screener said a few diamonds may not be natural and thismanufacturer does full screening before setting and guaran-tees natural. What the jeweler had no understanding of wasthat he had a screener, not a tester as he thought he was get-ting. All he really knew for sure was he had a TYPE IIa dia-

mond and since about 2% of all diamonds are TYPE IIa, hewill get “refer” as a result about two times per hundred tests.This is truly a paradox that will remain without a perfect an-swer for now. We await the next generation of testers. Willwe one day get that black box?

When buying a machine, do not expect 100% reliabilityand/or consistent results, from even the labs, because eachmanufacturer has slightly different specs and methods. Evenprominent labs can disagree on small LGDs. At the AGS con-ference this past February, diamond testers and screenerswere discussed. Harold Dupuy, Stuller VP of Strategic Analy-sis said it very plainly “No one piece of equipment availableto the average jeweler will work to identify 100% of the syn-thetic melee.” Even one of the developers of a testing device,Dror Yehuda (Yehuda company is the manufacturer of theSherlock Holmes) stated to me (RD) in Las Vegas, “Anyonethat tells you their machine has 100% accuracy is lying.” u

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