Lab Grown or Synthetic? The 2026 Diamond Nomenclature Split

The trade body that writes the diamond industry's terminology is about to rewrite it. CIBJO, the World Jewellery Confederation, is set to remove laboratory grown and laboratory created from its Blue Book and mandate synthetic as the sole term for a man made stone with essentially the same chemical composition, physical properties, and structure as its natural counterpart. Rapaport reported the September 2026 effective date on July 26, 2026, tied to the CIBJO Congress that opens in Vicenza on September 4, 2026.¹

The change goes further than a word. CIBJO's position is that the 4Cs grading scale, cut, colour, clarity, and carat, should apply to natural diamonds only. Udi Sheintal, who heads CIBJO's Diamond Commission, framed the reasoning plainly: when the 4Cs scale is used to describe synthetics, he argued, the consumer is misled into believing that a manufactured stone is rare in the way a natural one is.² It is a reversal of the inclusive terminology CIBJO adopted in 2010.

One caution belongs up front. A CIBJO Blue Book is a voluntary industry standard, not legislation. CIBJO is a representative trade body with United Nations ECOSOC consultative status, and its standards are widely referenced and feed into ISO work, but adoption is not legally mandatory across every jurisdiction. That distinction is the whole story of 2026, because the standards bodies and regulators are not moving together.

The difference between a synthetic and a lab grown diamond is a difference in wording, not in the object. Both terms describe the same thing: a diamond grown in a controlled setting rather than pulled from the ground. A lab grown diamond is pure crystallized carbon, Mohs hardness 10, with the same optical and chemical properties as a mined diamond. It is not a simulant. A cubic zirconia or a moissanite is a different material that imitates the look of diamond; a lab grown diamond is diamond.⁸

This is why the word matters to the people fighting over it. Standards writers who favour synthetic use the term in its precise gemological sense, an artificial product with essentially the same composition and structure as a natural one. The lab grown sector reads the same word the way most shoppers do, as a synonym for fake, and has long considered it pejorative.¹ Both readings are defensible. That ambiguity is exactly what makes the term a contested asset.

For a shopper the practical answer holds across every framework. Whether an invoice reads laboratory grown, laboratory created, or synthetic, the certificate describes one carbon crystal graded on the same measurable attributes. The vocabulary is a policy choice made in trade halls. The diamond in the setting is unchanged. For the deeper question of authenticity, see our note on whether lab grown diamonds are real.

The push comes from natural diamond interests. In May 2025, at a meeting in Sierra Leone, the African Diamond Producers Association, representing governments behind roughly 70 percent of global rough production, approved exclusive use of the 4Cs and carat weight for natural stones and called for synthetics to be measured in grams and labelled explicitly as synthetic. ADPA signalled it would lobby governments worldwide, with particular focus on the United States.⁹

Russia went further and made it law. Its government approved rules requiring lab grown stones to be called synthetic, barring standard diamond grades for them, requiring measurement in grams rather than carats, and reserving the trade term for a polished diamond to natural origin stones. Alrosa, the state linked miner, praised the decision.⁶ CIBJO's Diamond Commission is the standards arm of the same direction of travel.

The logic is commercial, and it is worth stating without heat. Natural producers benefit from a hard linguistic line: diamond and the 4Cs signal natural rarity, while synthetic, priced in grams, signals a manufactured good. Redrawing that line reframes lab grown away from luxury equivalence. This is a positioning move, presented as a consumer clarity initiative, and it arrives as lab grown continues to take share. By the 2025 data, lab grown accounted for 47.7 percent of engagement rings.⁷ The vocabulary fight is happening precisely because the product kept winning. We covered the wider structural break in the natural diamond bifurcation report.

There is no single global answer any more. A stone can be a laboratory grown diamond in the United States, a synthetic under CIBJO, Russian, and African trade frameworks, and a Premium or Standard graded stone on a GIA report, all at once. The table below sets out who uses which term, how binding it is, when it takes effect, and what a buyer actually sees.

Note the middle path. Under BIS IS 19469:2025, a national standard modelled on ISO 18323:2015, diamond used alone is reserved for natural stones, laboratory grown and laboratory created remain the permitted consumer terms, and synthetic is allowed only where commercial or import and export documents require it.¹⁰ It keeps the consumer word and confines synthetic to trade paperwork, sitting between CIBJO and the FTC rather than with either.

The United States is the counterweight. Its revised Jewelry Guides removed synthetic as a recommended descriptor and prefer laboratory grown, laboratory created, or a maker created disclosure, used clearly to show the stone is not mined. Using synthetic to imply a competitor's lab grown diamond is not an actual diamond would be deceptive. Tom Chatham, of Chatham Created Gems, put the US posture bluntly: what happened in Russia, he said, will not fly there, because the Federal Trade Commission exists to protect consumers from entities that want to eliminate competition.⁶

GIA's move is separate from CIBJO's, and it is already in effect. Since October 1, 2025 the laboratory has stopped applying the natural diamond colour and clarity nomenclature to lab grown stones. In place of a per stone 4Cs grade it issues a two tier descriptive result: Premium or Standard.⁴ GIA keeps the term laboratory grown and inscribes it on the girdle; it drops the letter and number grades, where CIBJO drops the word.

Pritesh Patel, GIA's president and chief executive, framed it directly: the institute will no longer use nomenclature created for natural diamonds to describe what is a manufactured product.⁴ For a buyer, this is the most concrete change on the page. A GIA lab grown report today reads Premium or Standard, so match that against the seller's claim rather than expecting a familiar colour and clarity pair. Many stones still carry IGI reports with full 4Cs grades, which is why reading the actual document matters. See our guide to reading an IGI certificate.

Very little changes about the object, and a fair amount changes about the paperwork. The physical product and its optical and chemical identity are the same as they were. What is shifting is vocabulary and grading presentation, and it will vary by market. A stone a Canadian or US seller must describe as laboratory grown may appear as synthetic in a CIBJO or Russian trade context, and its GIA report may now read Premium rather than a colour and clarity grade.

Draco's position is simple and it does not depend on which side wins the word. Every Draco diamond is IGI certified, E to F colour, VS2 and better, and a certificate travels with each stone. A report is checkable: the grades are measured, and an IGI report can be verified free at IGI.org. A label is a policy decision made by a trade body. So judge the diamond on its report, and treat the terminology as context rather than as a verdict on quality. That holds whether a document reads laboratory grown or synthetic, because it describes the same carbon crystal either way.

This report separates what is in force from what is announced, because regulatory dates move. Confirmed and in force: the GIA Premium and Standard system from October 1, 2025; the ADPA producer commitments from May 2025; the BIS IS 19469:2025 standard; and the FTC's pro laboratory grown stance with a review slated for 2028. Proposed and scheduled: the CIBJO Blue Book revision, reported effective September 2026 and formalized at the Vicenza Congress opening September 4, 2026, imminent but not yet the operative standard as of this writing.

Contested: whether synthetic displaces laboratory grown globally, or the United States holds the line and the market splits by jurisdiction, is actively disputed. The exact effective date of Russia's rules and the pace of ADPA's lobbying before the FTC's 2028 review are open. Methodology: every date and figure here traces to a named trade source, listed in the References with its publication date. Quotes are attributed to the outlet that reported them. Where a source characterizes rather than states a fact, such as the voluntary nature of a Blue Book, this report says so rather than presenting it as settled.

Last updated August 3, 2026. Figures verified against the named sources in the References.

Last updated August 3, 2026. Figures verified against the named sources listed below.