GIA Moves to Redefine Lab-Grown Diamond Grading, Signaling Clearer Divide from Natural Diamonds

Rough Lab-Grown Diamond

In a landmark decision that will reverberate through the global diamond industry, the Gemological Institute of America (GIA) the world’s foremost authority in gemology—has announced it will no longer use its internationally recognized 4Cs grading system for laboratory-grown diamonds. Instead, beginning later this year, lab-grown diamonds submitted to GIA will receive simplified descriptors—categorized broadly as either “premium” or “standard”—or no grade at all if the quality is subpar.

While GIA’s move to redefine lab grown diamond grading might sound like a simple nomenclature change, it’s much more than that. This move marks a definitive moment in the ongoing separation of natural diamonds from lab-grown diamonds. It confirms what many in the industry have long known: lab-grown diamonds are not the same as natural diamonds and should not be treated as such.

Why the 4Cs Is Essential for Natural Diamonds

GIA created the 4Cs—cut, color, clarity, and carat weight—as a rigorous system to help consumers understand the unique and complex qualities of natural diamonds. No two natural diamonds are exactly alike. They are rare geological miracles forged deep within the Earth over billions of years, each carrying a singular fingerprint from Mother Nature. A grading report for a natural diamond is essential because these stones exist along an immense spectrum of characteristics. 

Meet the Expert

GIA Moves to Redefine Lab-Grown Diamond Grading, Signaling Clearer Divide from Natural Diamonds
  • Grant Mobley is the Jewelry & Watch Editor of Only Natural Diamonds.
  • He is a GIA Diamonds Graduate.
  • He has over 17 years of jewelry industry experience, starting with growing up in his family’s retail jewelry stores.
Lab Grown Diamond grading: lab grown diamond
An uncut lab grown diamond

Why GIA Is Changing the Way Lab Grown Diamonds Are Graded

Lab-grown diamonds, on the other hand, are man-made and mass-produced using high-pressure high-temperature (HPHT) or Chemical Vapor Deposition (CVD) processes. According to Tom Moses, GIA executive vice president and chief laboratory and research officer, “More than 95% of laboratory-grown diamonds entering the market fall into a very narrow range of color and clarity. Because of that, it is no longer relevant for GIA to describe man-made diamonds using the nomenclature created for the continuum of color and clarity of natural diamonds.”Why Lab Grown Diamond Grading Needs a Different System

By replacing detailed grading reports with broader descriptors, such as “premium” and “standard,” GIA is drawing a clear line in the sand. They are telling consumers that these are not the same products and they should not be evaluated in the same way. And coming from GIA—the trusted nonprofit organization that established global diamond grading standards in 1953—this statement couldn’t be more authoritative.

Natural Diamonds: Rarity, Value, and Geological Identity

To understand why this change to lab grown diamond grading matters, it’s essential to examine what drives the value of natural diamonds: rarity and identity. Each natural diamond is finite, with unique growth patterns, internal inclusions, and color subtleties shaped by millions or even billions of years underground. These one-of-a-kind gems are the original luxury product—not just beautiful but rare and no longer forming in nature. Lab-grown diamonds, conversely, can be created in virtually unlimited quantities and replicated in appearance with astonishing ease. There is no rarity. There is no geological story. There is no true investment potential.

GIA Moves to Redefine Lab-Grown Diamond Grading, Signaling Clearer Divide from Natural Diamonds
Ring Courtesy of The Clear Cut
GIA Moves to Redefine Lab-Grown Diamond Grading, Signaling Clearer Divide from Natural Diamonds

Why Clarity in Lab Grown Diamond Grading Matters for Consumers

This distinction has become increasingly blurred by confusing marketing language and unclear labeling practices. Some in the lab-grown diamond space have leaned on the unsubstantiated language of “sustainability” and “equality” in comparison to natural diamonds, despite offering a fundamentally different product. But consumers deserve transparency. They deserve to understand what they’re buying, what it’s worth, and what makes one stone different from another. That’s precisely why this change from GIA is so important.

It’s also a return to the Institute’s founding principles. GIA exists to protect the public trust in gems and jewelry. With this shift, the Institute is ensuring that consumers can make informed choices without being misled by false equivalencies. By stepping away from the 4Cs for lab-grown diamonds, GIA is reaffirming its commitment to scientific integrity and public transparency.

GIA Moves to Redefine Lab-Grown Diamond Grading, Signaling Clearer Divide from Natural Diamonds
GIA Diamond Grading Report

Let me be clear: This is not about pitting one product against another. Lab-grown diamonds have their place in the market. But we must stop pretending they are interchangeable with natural diamonds. They are not heirlooms, they are not investments, and they are not rare.

GIA’s decision demonstrates that natural diamonds continue to be the benchmark of authenticity, value, and irreplaceability. They are not merely carbon crystals—they are ancient, unrepeatable creations of nature, each with a backstory written in geologic time.

As this policy rolls out in late 2025, expect other gem labs to follow suit. The line separating lab-created simulacra and natural geological masterpieces is being redrawn with bold ink—and GIA is holding the pen.

Source: Naturaldiamonds

US Tariffs: GIA Expands Dubai and Hong Kong Services

GIA Expands Dubai and Hong Kong Services

GIA says its Dubai and Hong Kong labs will accept larger stones for grading, in the wake of President Trump’s imposition of retaliatory tariffs on its trading partners.

Last week GIA said its US labs in New York and California would not accept submissions from overseas until confusion had been cleared up over the status of stones entering the country for grading rather than for sale.

In a statement on Monday (7 April) the world’s biggest grading lab said that because of tariff-related “logistical challenges” it was temporarily expanding services in Dubai and Hong Kong.

Dubai will now accept rough or polished diamonds (D-Z) up to 9.99-cts and Hong Kong will impose no size limit, until further notice.

Both labs previously had a 3.99-cts upper size limit. In addition, Hong Kong will now grade fancy color diamonds.

Source: IDEX

Downturn Forces GIA to Close Israel Lab

GIA is to close its lab in Ramat Gan, Israel, saying it is no longer "financially sustainable".

GIA is to close its lab in Ramat Gan, Israel, saying it is no longer “financially sustainable”.

The facility, which opened in August 2012, will close by the end of this year. Submissions will be sent to GIA labs elsewhere, with no additional shipping costs, the lab said in a press statement.

GIA was not able to say at this stage which other labs it would use (Dubai is the closest), or how much extra time that would take.

“Despite reductions in operating costs and reduced staffing through attrition, the laboratory is not financially sustainable,” said GIA, which grades the majority of the world’s polished diamonds.

“The GIA laboratory in Ramat Gan, Israel, will end operations by the end of 2024 due to changes in the global diamond industry that resulted in significant declines in submissions from local clients over the last several years.”

GIA closed its Antwerp lab in July 2022, citing “limited demand for services and financial performance that did not support continued operations”.

It also has labs in Bangkok, Hong Kong, Mumbai, Surat, Tokyo, Carlsbad, New York, Dubai, Gaborone and Johannesburg, according to its website.

From 17 November submissions to the Ramat Gan laboratory will be sent elsewhere. “GIA is working to establish a third-party process to accept submissions from walk-in clients in Ramat Gan for service in other GIA laboratories,” the lab said.

Source: IDEX

GIA Expands Fraud Checks to All Labs

GIA says it has expanded its new verification service – aimed at combating “cloned diamond” fraud – to all its labs.

The Report Confirmation Service was launched last month in New York to identify lab growns being submitted for regrading as natural diamonds.

GIA says the service is now available at all locations. It will accept walk-in and courier submissions, will turn around loose diamonds in as little as 15 minutes, and will, initially, make no charge.

The service is available for GIA-graded diamonds with and without inscriptions. An original GIA cert is helpful but not essential.

An increasing number of lab growns are being fraudulently submitted for re-grading. They are cut to match the specifications of natural diamonds that have already been graded and inscribed with either with a GIA number (genuine or fake).

“Combatting this fraud is vital to protecting the public and ensuring their confidence in gems and jewelry – this is GIA’s mission,” said GIA president and CEO Susan Jacques.

Source: IDEX

Italian Grading Lab Warns of Synthetic-Diamond Scam

Italian gemological lab Gem-Tech has warned the trade that a number of lab-grown diamonds circulating in the country are being sold as natural.

Three stones were submitted to the lab accompanied by certificates from the Gemological Institute of America (GIA) stating they were natural, Gem-Tech said last week. Gem-Tech weighed the stones and found them to be nearly identical to those recorded on the GIA certificates. The stones also had laser inscriptions with a visible GIA logo that matched those the lab had seen before from other GIA-graded stones, Gem-Tech explained.

However, further investigations indicated the stones had been fraudulently paired with the grading reports, while the inscriptions appeared to be forgeries.

When the Italian lab exposed the diamonds to ultraviolet light to detect fluorescence, it discovered that the stones were inert, whereas the reports described the level of fluorescence as “faint.” The diamonds were then checked using spectrophotometric analysis and displayed a distinct greenish coloration and other characteristics commonly found in synthetics created using chemical vapor deposition (CVD).

Once the lab checked the report numbers against the GIA website, it realized they were issued for other, natural, stones that were just slightly different than those submitted to Gem-Tech.

“Gem-Tech has seen this happen before,” the lab said. “It would not be the first time that malicious individuals obtained reprints of authentic reports and paired them with stones other than those described.”

Although there were only three stones submitted, Gem-Tech believes there might be more, it told Rapaport News.

“The client who submitted them for identification reported that these stones were not the only ones being offered,” the lab added. “Other dealers have mentioned that these three synthetic diamonds, identifiable by their report data, have been presented in other parts of the country.”

Source: Rapaport

Belgian Lab Detects Diamond with Fake Inscription

The diamond bearing the fake GIA inscription.

HRD Antwerp recently discovered a fake inscription on a polished diamond the lab had received for grading.

The 1.50-carat stone had a Gemological Institute of America (GIA) laser inscription corresponding to a natural grading report, HRD said Monday. The accompanying report listed the diamond as natural, with no color treatments. The stone was further identified as type IIa, meaning it contained virtually no elements other than carbon. However, during testing, the Antwerp lab found that the diamond had undergone High Pressure-High Temperature (HPHT) color treatment.

Although the diamond’s carat weight, color and cut precisely matched the GIA report, HRD noticed inconsistencies with clarity characteristics that were quite similar to those listed in the certification and could easily be mistaken during a standard loupe inspection, it explained.

“Detailed microscopic investigation by an experienced grader revealed that this was not the same diamond described in the report,” HRD said. “The clarity characteristics did not completely overlap. Since these characteristics are a unique fingerprint of the diamond, the inscription was conclusively identified as false. The diamond at hand had been intentionally inscribed with a fake laser inscription to deceive the customer.”

Correction: The story has been updated to clarify what was disclosed in the report and the findings of HRD.

Source: diamonds.net

Gemmological Institute of America seven week graduate diamond diploma

Gemmological Institute of America

The GIA a gemmological organisation will be conducting a seven week graduate diamond diploma from January 8.

The programme combines theory lessons with practical hands on learning and will be held in Jaipur.

Students will learn how to grade in accordance with the GIA’s 4Cs colour, cut, clarity and carat weight of diamond in the D-Z colour range.  

As well as how to grade diamonds and detect simulants and treatments like fracture filled diamonds using gemmological equipment.

The course will be taught by instructors from the Mumbai campus.