SourcingAug 12, 2026
Eshed-Gemstar on the Painstaking Process of Cutting ‘The Legacy Emerald’The gemstone supplier and manufacturer acquired the remarkable 104-gram Zambian emerald at Gemfields’ auction in May.
EditorsOct 20, 2016
Why the GIA Grades Lab-Grown Diamonds Like It Does
The GIA’s Tom Moses explains the reasoning behind the more general color and clarity grades the lab assigns to synthetic stones.
The 5.19-carat diamond on the left and the 10.08-carat blue diamond on the right are both lab-grown stones recently examined by the Gemological Institute of America’s laboratory in Hong Kong. (Photo credit: left picture, Terry Leung and Johnny Leung; right picture, Johnny Leung, both courtesy of GIA)
Earlier this week, I wrote a story about two large lab-grown diamonds--one 5.19 carats and the other a 10.08-carat blue--recently examined by the Gemological Institute of America’s laboratory in Hong Kong.
In both articles, I noticed the GIA using the following terminology to refer to the stones’ color and clarity: “J-equivalent color” and “VS2-equivalent clarity” for the white diamond, and color equivalent to “fancy deep blue” for the colored stone.
This terminology, for me at least, raised questions about the GIA’s approach to grading synthetic diamonds.
On Wednesday, the very knowledgeable Tom Moses, the GIA’s executive vice president and chief laboratory and research officer, took some time to explain it to me.
Moses said the GIA has been issuing Synthetic Diamond Grading Reports for about 10 years.
On these reports, the GIA does not give specific color or clarity grades.
Instead, Moses said, it grades lab-grown diamonds in broader terms, calling, for example, stones in the D-E-F range “colorless” and those in the G-H-I range “near colorless.”
For clarity, the lab uses only VVS, VS, SI or I for synthetic diamonds.
Why?
Because, “by their very nature, when they grow these diamonds, they are traditionally nitrogen poor,” Moses said, which is, incidentally, also what makes them Type IIa. In addition, many, though not all, CVD-grown diamonds come out a sort of brown color and then are de-colorized through a treatment process to make them colorless or near colorless.
All this is to say that these stones are not going to have the same range of color (D to Z) as mined diamonds, which is why the GIA chooses to use broader categories in grading them. They are grown to be as clear as possible, too, which is why the GIA also uses broader terms for clarity.
The GIA’s grading system, which was created long before the proliferation of lab-grown stones that we see today, was “developed for normal mine run, which doesn’t change. That’s nature,” Moses noted.
However, when the GIA publishes research articles online--like this one on the 5.19-carat diamond that appeared earlier this month--it uses terms such as “J-equivalent color” and “VS-equivalent clarity” to give readers a clearer picture of the stone.
Moses said despite what some people seem to think, the GIA is not doing this to “punish diamond growers.” Rather, the lab just sees it as the most logical way to describe lab-grown diamonds.
In both articles, I noticed the GIA using the following terminology to refer to the stones’ color and clarity: “J-equivalent color” and “VS2-equivalent clarity” for the white diamond, and color equivalent to “fancy deep blue” for the colored stone.
This terminology, for me at least, raised questions about the GIA’s approach to grading synthetic diamonds.
On Wednesday, the very knowledgeable Tom Moses, the GIA’s executive vice president and chief laboratory and research officer, took some time to explain it to me.
Moses said the GIA has been issuing Synthetic Diamond Grading Reports for about 10 years.
On these reports, the GIA does not give specific color or clarity grades.
Instead, Moses said, it grades lab-grown diamonds in broader terms, calling, for example, stones in the D-E-F range “colorless” and those in the G-H-I range “near colorless.”
For clarity, the lab uses only VVS, VS, SI or I for synthetic diamonds.
Why?
Because, “by their very nature, when they grow these diamonds, they are traditionally nitrogen poor,” Moses said, which is, incidentally, also what makes them Type IIa. In addition, many, though not all, CVD-grown diamonds come out a sort of brown color and then are de-colorized through a treatment process to make them colorless or near colorless.
All this is to say that these stones are not going to have the same range of color (D to Z) as mined diamonds, which is why the GIA chooses to use broader categories in grading them. They are grown to be as clear as possible, too, which is why the GIA also uses broader terms for clarity.
The GIA’s grading system, which was created long before the proliferation of lab-grown stones that we see today, was “developed for normal mine run, which doesn’t change. That’s nature,” Moses noted.
However, when the GIA publishes research articles online--like this one on the 5.19-carat diamond that appeared earlier this month--it uses terms such as “J-equivalent color” and “VS-equivalent clarity” to give readers a clearer picture of the stone.
Moses said despite what some people seem to think, the GIA is not doing this to “punish diamond growers.” Rather, the lab just sees it as the most logical way to describe lab-grown diamonds.
Editors' Picks
Sponsored by
He added that from a consumer perspective, he doesn’t think there is that much demand for specific color grades for lab-grown diamonds. Rather, they’re just happy to have a ring or a pair of earrings that are real diamonds but for a lower price.
“They’re going to say, ‘It looks nice. They sparkle. They’re the price I want to spend. I’ll take them.’”
(I think this same argument could be made for mined diamonds as well, but that’s another topic for another time.)
Moses said while lab-grown diamond companies do ask the GIA to do it differently, he doesn’t see the GIA altering its system in the near future, especially with the improving diamond-growing technology producing more stones of high color and clarity.
“Our mission is to serve the consumer and provide clear and accurate information,” he said. “Although we listen to the industry, ultimately, we are here to serve the public.”
“Right now, I just don’t see a reason why we would make that change.”
More on Editors
The Latest
CrimeAug 12, 2026
Elderly NYC Woman Targeted in Jewelry Swap SchemeTwo suspects offered to trade the woman a “winning” lottery ticket for her jewelry.
SourcingAug 12, 2026
Another Diamond Mine Poised to CloseFinsch has been in business rescue since May, and owner Petra Diamonds said it sees no viable path forward for the mine.
Brought to you by
Why More Jewelry Retailers Are Hosting Turnkey Estate Buying EventsRetailers are seeking new ways to attract customers, increase traffic, and create revenue – Estate buying events are a popular solution.
CrimeAug 12, 2026
Jewelry Store Employee Gets 20 Years to Life in Choking Death of BossMichel Patrick DeSalles was sentenced after pleading guilty to the 2017 murder of Omid Gholian, who owned a jewelry store in Manhattan.
Weekly QuizAug 07, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
MajorsAug 12, 2026
Frederick Goldman Names New SVP of SalesLongtime industry executive Beth Miller has taken on the role.
AuctionsAug 11, 2026
Verdura Unicorn Brooch With Royal Connection Up for Auction The brooch was owned by Virginia Fortune Ryan Ogilvy, who served as a lady of the bedchamber to Queen Elizabeth II for nearly 50 years.
Brought to you by
Wedding Band Trends 2026: Personalization Takes Center StageColored gemstones, artisan finishes, mixed metals, and meaningful details are shaping demand in bridal jewelry.
MajorsAug 11, 2026
Signet Jewelers Selects Mattel Exec to Lead Zales, BanterJamie Cygielman will take on the role on Aug. 24.
IndependentsAug 11, 2026
Polly’s Fine Jewelry Co-Owner Richard Moore Dies at 69Moore, Polly’s husband, is remembered as a family man with an easygoing spirit and a love for sports and the outdoors.
ColumnistsAug 11, 2026
Creative Connecting: How to Sell Colored Gemstones to Gen ZDuvall O’Steen and Jen Cullen Williams share the best ways to display, present, and explain colored gemstones to younger customers.
Events & AwardsAug 11, 2026
NAJA Announces Lineup For 2026 Fall Virtual ConferenceThe mid-year conference for jewelry and watch appraisers will take place Sept. 5-6 on Zoom.
TechnologyAug 10, 2026
Colorado Jeweler Launches Customization Tool He Built HimselfHonest Hands Ring Co. Founder Benjamin Bosworth shared his thoughts on jewelry technology and why AI can never replace the human element.
MajorsAug 10, 2026
QVC Exits Chapter 11 Bankruptcy, Names New Interim CEOQVC Group President and CEO David Rawlinson is temporarily being replaced by a familiar face, former QVC CEO Mike George.
CollectionsAug 10, 2026
State Property Puts a Ripple in the ‘The Voyager’ CollectionThe brand also added two one-of-a-kind brown diamond pieces to the “Sanssouci” series of its “Gardens” collection.
MajorsAug 10, 2026
And IJO’s 2026 Vendor of the Year Is … Ostbye took home top vendor honors at the Independent Jewelers Organization’s show, held last month in Kentucky.
Supplier BulletinAug 07, 2026
Why More Jewelry Retailers Are Hosting Turnkey Estate Buying EventsSponsored by Stratus Estate Buyers
MajorsAug 07, 2026
Retail Veteran Pam Cloud Appointed President of Blue NileCloud, who will officially join Blue Nile on Monday, spent 26 years at Tiffany & Co. and founded jewelry brand Roseate.
MajorsAug 07, 2026
Pandora Appoints Paulo Garcia as New CFO Garcia will take over from the company’s current CFO, Anders Boyer, who is retiring at the end of November.
MajorsAug 07, 2026
Etsy to Lay Off 12% of WorkforceEtsy CEO Kruti Patel Goyal explained why the company is letting go more than 200 employees as its performance improves.
TrendsAug 07, 2026
Look Ahead with Syna’s Binoculars PendantThe “Star Gazer” pendant, our Piece of the Week, is Syna’s tribute to curiosity and the discovery of something new.
CrimeAug 06, 2026
Lalique Museum to Remain Closed Following $5M HeistMuseum officials are looking to the public to help cover the “exceptional” costs involved in recovering from the July 5 smash-and-grab.
MajorsAug 06, 2026
Claire’s Revamps Piercing Services for Second Time in Three Years The overhaul includes enhanced employee safety training and trendy earring styles, including lab-grown diamond studs.
FinancialsAug 06, 2026
Brilliant Earth’s Q2 Sales Up 6%, Driven by High-Income ShoppersThe retailer said it had its biggest Mother’s Day ever, with strong demand for higher-priced jewelry.
TrendsAug 06, 2026
New Book on Handcrafted American Objects Highlights Jewelry“Handwork: Handcrafted Objects that Made America” features historic and contemporary works, including a Diné squash blossom necklace.
MajorsAug 06, 2026
AJA East Coast Names Ani Khachian as First Female President-ElectThe Armenian Jewelers Association’s East Coast chapter has also elected its 2026–2027 board of directors.
MajorsAug 05, 2026
Private Equity Firm Wants to Buy 100+ JCPenney StoresOnyx Partners has submitted a second offer to buy the department stores after its first offer fell through last year.
