Third Anniversary of GIA’s Strategic Service Arrangement With Stuller

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We’re celebrating the third anniversary of Stuller’s strategic service arrangement with GIA — the Gemological Institute of America® — at its Lafayette, LA facility. Melee diamonds, which weigh less than 0.2 carats, are dazzling accents in many pieces of jewelry and watches. In addition to natural melee, there are many laboratory-grown and simulated melee diamonds on the market. However, these sometimes get mixed in with parcels of natural diamonds.

How can a jeweler know for sure that their diamond from Stuller has been screened and is indeed a natural diamond? The answer is Melee Analysis by GIA®. In 2018, GIA brought this fully automated service onsite to Stuller. An advanced instrument developed through decades of GIA research sorts diamonds by identity, diameter, and even color range. Once sorted, each melee result type is provided back to Stuller.

When ordering GIA-screened melee from Stuller, you will receive a gray parcel sealed with a GIA sticker that signifies that your diamond has been screened by Stuller’s in-house GIA Melee Analysis service.  

One huge improvement to this arrangement at Stuller is the addition of a second GIA screening machine. This allowed GIA to handle Stuller’s large melee volume. In total, GIA has evaluated more than 6.5 million melee stones for Stuller through this arrangement. The goal is to give consumers confidence when purchasing natural melee diamonds — the most prevalent stones on the market. This arrangement serves GIA’s consumer-protection mission of ensuring public trust in gems and jewelry.  

Stanley Zale, Stuller’s vice president of diamonds and gemstones procurement, believes that “a strong, continuous collaboration between Stuller and GIA leadership provides unparalleled confidence as GIA is the most trusted gemological authority in the industry. There is no one better than GIA for Stuller to rely on to deliver on our commitment to correctly represent the product we are selling.”

Lab-Grown Diamonds: Let’s be completely clear, Part 1

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As Lab-Grown Diamond (LGD) sales continue to grow with no end in sight, complete transparency — for you and us — has never been more important. None of us want to damage trust by selling a LGD as a Natural Diamond or a natural as a Lab-Grown diamond. LGDs are chemically, optically, and physically similar to Natural Diamonds, however they are created in a lab rather than 150 miles below the earth’s surface. LGDs have scintillating radiance, at a more attractive price. All customers need to know this.


In this first blog on transparency, we’ll look at how we make sure you know you are buying an LGD from Stuller. And the second blog will discuss your responsibilities when selling a LGD or LGD-set jewelry.

The following steps mark the individual efforts Stuller takes to provide you with transparency in purchasing Lab-Grown Diamonds from us.

Buy from reputable partners

If we don’t know exactly what we’re buying and receiving, how can we give you that same assurance? We purchase our Lab-Grown Diamonds from reputable vendors with a proven track record, and they are required to screen their product before shipping it to us. We back this up by screening all colorless and near-colorless Diamonds that enter our facility.

Stuller has a strategic service arrangement with GIA (Gemological Institute of America®). As an independent entity from Stuller, located in our facility, it is staffed by GIA’s screening specialists, who use GIA’s proprietary technology to perform the work. GIA’s instruments screen round melee diamonds in sizes 0.005 CT through 0.24 CT. The technology also sorts and color grades (D-to-Z) natural diamonds into color ranges.  You can learn more in our Diamond Screening Guide.




When you shop on Stuller.com, Lab-Grown Diamonds have their own clearly marked categories to eliminate confusion. All loose LGDs and LGD set jewelry — online and in catalogs and brochures — have the LG badge in a particular blue color. And all product descriptions include “lab-grown diamond.” If you shop by phone, our Diamond Specialists specifically address Natural Diamonds vs. LGDs and explain the differences so you can share this information with your customers.

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Storage & Protocols

We store Lab-Grown Diamonds in separate vaults from our Natural Diamonds. And to avoid any possibility of mixing them, Diamond Specialists cannot have both types of diamonds on their desks at the same time.

Packaging & Invoices

We sell three levels of Lab-Grown Diamonds: large stones with a GCAL certificate or IGI report, large stones without reports, and melee. We store and ship the large LGDs with reports in a distinctive blue box that you can immediately identify as an LGD. The large stones without reports and the melee arrive wrapped in a blue paper nearly identical to the box color.

Your invoice will also state that you purchased one or more Lab-Grown Diamonds.

If you have any further questions about Lab-Grown Diamonds, call 800-877-7777, ext. 5 to speak with a Diamond Specialist.

Watch for the follow-up transparency blog later this month. It will address what and how you need to share LGD information when you sell them.

Diamond Education: How to Choose the Right Diamond Screener?

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Protecting the integrity of your inventory is paramount. Understanding the differences between testing and screening while using the most appropriate instruments for each process will best protect your reputation.

Selecting an Instrument

With lab-grown Diamonds gaining a stronger presence in the marketplace, screeners and testers are no longer optional to include in your operations. They’re essential.

When purchasing a diamond screener or tester, ask yourself the following:

  • What stone specifications (size, color, shape, and loose or mounted) will I be testing?
  • How many stones will I be processing at a time — singles or large quantities?
  • What is my level of expertise with testing?
  • Do I need a portable or stationary instrument?
  • What is my budget?
  • Do I need to test for simulants?

Once you have your answers, you can identify the devices that fit your needs.

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Best Practices

  1. Remember, no single device can do it all — no exceptions.
  2. Understand your tester’s capabilities. Then, choose a device based on the features you need.
  3. Avoid false readings due to improper usage. False readings — such as a Diamond reading as a created Moissanite — may occur by holding your device improperly or testing on a nonconductive material. So, it’s imperative to read your device’s user manual. For added security, practice on known stones.
  4. Keep up with the latest technology. If it’s been years since you last bought a tester, look into newer devices. Each year, testing technology gets better, so older instruments may not have modern testing capabilities.

Diamond Testers

Testing is the process by which Diamonds are definitively identified. These instruments typically separate stones based off their thermal and electrical conductivity, but they have their limits. Learn the limitations of your tester and know when to bring in another device (or send it off to a lab with more advanced equipment). Shop Diamond testers on Stuller.com.

Diamond Screeners

Screening is the process by which mined Diamonds are separated from lab-grown Diamonds. Since it’s impossible to identify a Diamond’s growth origin by sight alone, screening equipment is the surest way to determine whether a Diamond is mined or lab-grown.

Furthermore, screening is distinctly different from detection, which involves positive identification of a mined Diamond, lab-grown Diamond, or simulant. Find the right Diamond screener on Stuller.com.

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Introducing the DiaTrue Diamond Scanner

The DiaTrue CS and the DiaTrue CXL by OGI Systems are instruments that combine the functionality of multiple machines to ensure maximum security. These machines can detect and identify:

  • Mined Diamonds
  • HPHT lab-grown Diamonds
  • CVD lab-grown Diamonds
  • Created Moissanite
  • Cubic Zirconia
  • CVD-Coated Cubic Zirconia and Moissanite

Both scanners have an embedded 10.9-inch touch screen that displays results in clear, easy-to-read colors. These machines can archive stone data for later use as well as create and print certificates.

The new DiaTrue CXL features a 13×10 cm tray space to accommodate larger parcels, finished goods, watches, and more.

Why do I need a Diamond Screener?

Diamonds enter your store from many sources. Whether buying Diamonds from a dealer or taking in jewelry for repairs and remounts, there are many opportunities for undisclosed stones to enter your stock. You must be absolutely certain of your inventory and take all measures to avoid undisclosed lab-grown Diamonds — because your reputation is at stake.

Luckily, the DiaTrue combines the functionality of multiple machines to ensure total assurance. This device can detect natural Diamonds, CVD and HPHT lab-grown Diamonds, Cubic Zirconia, and Moissanite — all in one scan. Operate with confidence knowing you’ve got the right tool to positively identify lab-grown Diamonds and simulants.

Shop the DiaTrue Diamond Scanner on Stuller.com

Once you choose the right diamond screener, you’ll be on your way to passing peace of mind to customers and securing your reputation as a trusted professional.

Diamond Education: How Does Stuller Uphold Its Diamond Screening Promise?

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How many undisclosed Lab-Grown Diamonds are you willing to sell? For Stuller, the answer is zero. That’s why we screen 100% of all colorless and near-colorless diamonds that pass through our hands. We uphold our diamond screening promise to protect you, the independent jeweler, your customers, and the industry. It is a question of integrity. It’s also a requirement of the FTC Guides for the Jewelry Industry.

How does Stuller uphold its Diamond screening promise?


Many years ago, when Stuller began screening for undisclosed lab-grown Diamonds, we took several important steps. We reviewed every way a Diamond entered our building and evaluated the risk levels based on the probability of contamination associated with each supply. This helps everyone down the pipeline to understand risk levels associated with each avenue into Stuller.

From there, we developed new processes or modified existing procedures to ensure that we screen all Diamonds arriving at Stuller. In short, we leave no Diamond unturned or unscreened.

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Our Diamond Screening Promise

As a major supplier, we are in a position to protect our supply chain, your reputation, and your customer’s confidence. We gladly accept this responsibility by maintaining:

  • A zero-tolerance policy for Undisclosed Lab-Grown Diamonds that places stringent testing requirements on all of our suppliers.
  • The Stuller Gem Lab, an advanced diamond screening lab managed by a full-time Graduate Gemologist.
  • A strategic services arrangement with GIA® to screen and color grade all round melee sizes 0.005 CT through 0.24 CT.
  • The ability to screen all shapes and sizes of colorless and near-colorless melee (D to N) as well as set jewelry.
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Diamond Screening Milestones

2012: Stuller begins screening all Diamonds 15 carat and larger for ULGDs using an early screening machine.

2014: Stuller acquired the sophisticated Automated Melee Screening Device (AMS) from DeBeers’ IIDGR division. It screens round Diamonds 1.4mm and larger providing an effective and efficient way to test melee.

2016: Stuller added IIDGR’s (DeBeers) PhosView, which allowed us to screen all shapes that are High-Pressure High-Temperature (HPHT) grown.

2017: Stuller added the AMS2 (the second generation of the original AMS) to our Diamond screening process. This technology screens round and fancy shapes, as small as 0.85mm detecting both HPHT and CVD grown Diamonds, screening 10 times faster (3,600 stones per hour) than the original AMS (which we continue to use).

Stuller added the GIA® iD100which combines advanced spectroscopic technology to identify natural Diamonds giving results in two seconds.

2018: Stuller added the J-Smart Plus to batch screen all Diamond-set products. Stuller also added the DiaTrue CS (by OGI) to screen set rings and parcels of stones.

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Stuller Gem Lab

Stuller Gem Lab uses the latest advanced technologies available to separate natural Diamonds from their lab-grown counterparts. These two supplies are kept totally separate from one another. Their paths never cross to ensure complete confidence. All lab-grown melee Diamonds are kept in a separate room within the facility, and their containers are clearly labeled.

To stay at the forefront of Diamond screening, we continuously invest in the latest technology. The Stuller Gem Lab has a multi-tier screening process managed by a full-time graduate gemologist. All colorless and near-colorless Diamonds and Diamond jewelry entering our facility are screened on an array of technologies depending on shape and size. Referrals from these screening technologies receive a final determination from our gemologist who performs further screening or is sent to a GIA® Advanced Lab.

Diamond Screening Promise Gem Lab

GIA® Melee Analysis

In addition to all of these internal controls, Stuller has established a strategic service arrangement with GIA (Gemological Institute of America®) by offering GIA’s Melee Analysis Service inside our global headquarters in Lafayette, Louisiana. All round melee from sizes 0.005 CT through 0.24 CT are screened on-site by GIA staff independently operating the GIA-owned analytical instrumentation in a dedicated, secure space.

This results from a strong continuous collaboration between Stuller and GIA leadership. GIA is the most trusted gemological authority in the industry. Therefore, there is no one better than GIA for Stuller to rely on to deliver on our commitment to correctly represent the product we are selling.

Learn more about Stuller’s extensive diamond screening promise here on Stuller.com

Zale’s Tales: JCK Las Vegas 2018

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As I write this, I’m still recovering from JCK. It’s amazing how in a week’s time we can go from feeling excited about the upcoming show to wanting nothing more than to get out of Vegas and head home. Besides the primary mission of seeing our customers, there was a lot of activity regarding some issues that are critical to our industry. Among those are:

1. Blockchain Technology

This seems to be everywhere these days, and JCK 2018 was no exception. Very simply put, Blockchain is nothing more than a web-based utility that allows for the secure storage and transfer of data. There are a variety of Blockchain initiatives swirling around the industry, some initiated from the supply and manufacturing side, another from the customer-facing side, and even initiatives in the midstream. But what does this all mean for the independent jeweler, whether traditional brick and mortar, web-based, or Omni-channel? Not a lot so far. It’s a new game, but the world is quickly adapting.

As it was explained to me, Blockchain is nothing more than a new internet protocol, which in a few years will be as ubiquitous as HTTP and SMTP, and none of us will need to know how it functions; it will just be! In the immediate term, we need to allow the various Blockchain developers to bring their initiatives further along to the point of easy adoption. At the end of the day, the benefit will be better transparency of the industry supply chain, which will serve to validate responsible sourcing protocols. And that is the underlying problem that utilizing Blockchain will help solve.

Here’s a quick overview of Blockchain technology


2. Screening for Undisclosed Lab Grown Diamonds (ULGDs)

This is a big topic, as it sits at the heart of consumer confidence. Along with my colleague Harold Dupuy, it seemed as though every time we turned around there was someone else with another screening device. Harold offers some great insight; all the instruments out there, for the most part, use one or some combination of the following six existing technologies:

1. UV Transparency vs Opacity

2. Infrared absorption spectroscopy (FTIR)

3. NIR absorption spectroscopy (UV-Vis)

4. Laser photoluminescence spectroscopy (PL)

5. Phosphorescence & decay speed

6. Fluorescence spectroscopy


To remain vigilant, Stuller has implemented the following advanced instruments into our QA process: IIDGR’s new AMS2, GIA’s iD100, and Raman, UV-Vis, and FTIR spectrometers. We’ve also welcomed GIA to Stuller to conduct independent melee analysis services.

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Shop diamond & gemstone testers on Stuller.com

Farewell, JCK Las Vegas 2018

At the end of the day, this is an industry of relationships, and what I value most about JCK is seeing old friends. Whether it was having morning coffee with someone I learned diamond sawing with (longer ago than I want to admit), attending seminars with a former colleague, or having dinner with my daughter Olivia — the fifth generation of our family in the jewelry business — it’s all about the people!

Oh, by the way…did anyone else hear a rumor that De Beers is now selling lab-grown diamonds? Okay, okay. I know that’s what everyone wants to hear about. Wait, what’s that? I’ve already exceeded my word allocation for this blog entry?

Sorry, I guess Lightbox will have to wait for another time.