Do you verify that every diamond that comes through your doors is, indeed, a natural diamond?

If not, you should: investing in diamond screeners and stone testers is one of the easiest ways you can protect your reputation — right in the comfort of your own store, right in front of your customers.


    1. Customer repairs

    2. Loose melee

    3. Semi-set pieces

    4. Loose large stones

    5. Finished jewelry

These are just a few pathways stones come through your store and can potentially get mixed in with your existing stock.

Think you have nothing to worry about? In early 2017, the GIA lab in Mumbai screened a melee parcel — and discovered nearly one-third of the stones were undisclosed CVD lab-grown diamonds, each stone mistakenly represented as a natural diamond.

Stuller has made several efforts to protect against this very scenario. Just last year, GIA® (Gemological Institute of America®) brought its gemological expertise right here inside Stuller’s facilities in Lafayette, Louisiana. Thanks to a pioneering strategic service arrangement, Stuller’s melee is screened by the GIA Melee Analysis Service for diamond parcels coming through the building. GIA staff are on site as they independently operate the GIA-owned system in a dedicated, secure space.


To safeguard the integrity of diamonds in your store, it’s worth knowing how you can protect yourself. Ask yourself these six questions:

    1. Am I screening loose or mounted jewelry?

    2. Am I screening single stones or batches of stones?

    3. Am I screening center stones, melee, or both?

    4. Do I want a manual or automated instrument?

    5. Do I want to screen for HPHT diamond, CVD diamonds, or both?

    6. Do I want to screen for simulants?

Once you know your needs, you can decide whether a diamond screener or stone tester — or even both — is right for you.


Each item highlighted below must be used correctly for accurate results, so we recommend carefully reading the instructions that come with each tool and practicing on a variety of verified stones first to ensure you’re using the tool correctly.

It can even be a fun training exercise to do with your staff to ensure everyone knows how to properly screen and/or test stones.

Note: No single screener or tester can perform every function. For maximum security, understand the limitations of all instruments.


Diamond screening is the process by which natural diamonds are separated from lab-grown diamonds. Since lab-grown diamonds are physically, chemically, and optically identical to mined diamonds, it is impossible to distinguish their differences by sight alone.

To identify the differences between natural and lab-grown diamonds, screeners use short-wave ultraviolet light. Proper screening assures total confidence in your stock and stops any undisclosed lab-grown diamonds from landing on your sales floor.

Now you're on your way to achieving a great finish with your rhodium plating. But, if you're still not getting the results, you want, just give us a call, email, or live chat with us. We're here to help.

DiaTrue CXL

  • Detects CVD and HPHT lab-grown diamonds, Moissanite, and bulk parcel of loose diamonds
  • Identifies stones on small jewelry settings like rings, bracelets, pendants, earrings
  • 10.9" touch screen display
  • 13x10 cm tray space
  • Size range: 0.003ct(0.9mm)-50 carats

DiaTrue CS Scanner

  • Detects CVD and HPHT lab-grown diamonds, can also see CZ, Moissanite, and even CZ coated with CVD
  • Identifies stones on small jewelry like rings, unmounted diamonds and melee parcels
  • Scans in approximately 20 sec
  • Large embedded 10.9” touchscreen tablet
  • Results displayed in clear and easy to read colors

DiaTrue Mobile

  • Detects CVD & HPHT lab-grown diamonds, Moissanite and CZs
  • Identifies stones on jewelry, unmounted diamonds and melee diamond parcels
  • Size range: 0.001 CT - 50 CT
  • Dimensions: 7.7" L x 5.1" W x 4.7" H
  • Real time function for precise stone identification with results in 1 second that then can shared via mobile devices
  • 8 x 9 cm test area
  • Comes with a carry-on bag, ring tray, rotating ring holder and black/white trays

GIA® iD100™

This screener uses advanced spectroscopic technology to distinguish colorless to near-colorless natural diamonds from lab-grown diamonds and simulants.

This easy-to-use desktop instrument screens both mounted and loose diamonds 0.9 mm or greater in diameter (approximately 0.005 carats), delivering results in under two seconds and letting you know whether the diamond passes or refers for further testing.


This screener distinguishes colorless to near-colorless diamonds from lab-grown by measuring the diamond’s opacity or transparency under ultraviolet light.

The screener’s color-coded light bars immediately indicate whether the diamond is natural or possibly lab-grown. This machine screens diamonds as small as 0.02 carats to as large as 10 carats, whether loose or mounted (as long as there’s an open back for light to pass through).


Diamond testing is the process by which diamonds (both natural and lab-grown) are separated from moissanite, cubic zirconia, white sapphire, and other simulants.

These instruments often separate stones based on their conductivity — however, note that most diamonds are not electrically conductive, whereas Charles & Colvard Forever One™ Moissanite has low electrical conductivity. This caveat is important to consider when shopping for a diamond tester.


This portable, easy-to-use device tests for colorless diamonds, moissanite, and other simulants.

The probe tip (included) can test colorless diamonds as small as 0.02 carats. But with the micro-probe tip (separately available), it can test colorless melee as small as 0.01 carats. This tester identifies stones based on their electrical conductivity, including stones with low conductivity, such as Charles & Colvard Forever One™ Moissanite.


This durable tester uses low-conductivity testing technology to test colorless diamonds, moissanite, and white sapphires. It identifies stones based upon their electrical conductivity, including stones with low conductivity (such as Charles & Colvard Forever One™ Moissanite), and delivers results through color-coded indicators.


This tester verifies the authenticity of colorless diamonds against moissanite, cubic zirconia, and other simulants. It tests stones based upon their thermal and electrical properties, although it cannot test low-conductivity moissanite like Charles & Colvard Forever One™ Moissanite. The retractable probe tip is 0.6 mm, allowing this device to test stones as small as 0.02 carats.

If you think these instruments are expensive, consider the cost of unintentionally selling a lab-grown diamond or simulant as a natural diamond. Then ask yourself one question: “What is my reputation worth?”

Stuller has a zero-tolerance policy toward undisclosed lab-grown diamonds. Learn more about our rigorous screening process at

As always, if you need help with tools or questions about metals or soldering, contact Stuller’s Tools Tech Team. Give them a call at 1-800-877-7777 ext. 4300
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