Made public on 26 August 2026, a rule adopted in June 2026 now requires AGTA members to use the word synthetic when describing a manufactured gem. It sits in the revised code of ethics, which every member signs each year : the term lab-grown may no longer stand alone.
Eight months earlier, on 1 October 2025, GIA had stopped using for laboratory-grown stones the colour and clarity nomenclature it had itself created for natural diamonds. Two withdrawals of vocabulary in eight months, on a stone no gemmologist can tell apart by eye.
average price of an American engagement ring set with a laboratory-grown diamond in 2025, against $7,000 for a ring set with a natural diamond, while the laboratory stone is on average larger : 2 carats against 1.6
According to the study published by The Knot on 18 February 2026, covering more than ten thousand couples married in 2025, 61 % chose a laboratory-grown centre stone, a rise of 239 % since 2020 ; the halfway mark had been crossed in 2024. The cheaper stone is the larger one, and it is the one most often bought. Here the price measures no property of the stone : it measures where the carbon crystallised.
A Stradivarius carries its proof in its wood. The One-Cent Magenta carries it in its ink. A bitcoin from 2009 carries it in its block height. The natural diamond carries nothing. GIA states it plainly : because laboratory-grown stones are « essentially chemically and optically the same » as natural ones, traditional gemological observation and instrumentation cannot tell them apart.
Nine issues have dealt with objects that carried their proof. Here are two objects that carry none.
In 2018, De Beers launched Lightbox and sold its laboratory-grown stones at $800 a carat, on a linear price list. On 8 May 2025 the group announced the closure of the brand : since launch, it wrote, wholesale prices for laboratory-grown diamonds had fallen 90 %. Element Six, the subsidiary that produced them, refocused on industry.
The natural stone is not spared : De Beers' average realised price per carat fell to $105 in the first half of 2026, down 32 % year on year. Neither drew its price from geological scarcity : one had a discipline of supply, the other had nothing.
The assessment no longer states a colour or a clarity : it states « premium » or « standard ». A stone that fails to reach the minimum threshold receives no designation, and its owner still pays $5. The price list does not measure the stone ; it measures what the laboratory is still willing to say about it.
The diamond is the archetypal object of inheritance, and yet its chain is almost never documented : outside historic stones, a ring changes hands without register, without name, without date.
What is transmitted, and counted, is the company that sold the story. De Beers was worth $17.6 billion when it was taken private in 2001. Its book value fell from $9.2 billion in 2023 to $2.3 billion in early 2026, after three consecutive impairments for the 2023, 2024 and 2025 financial years : 1.6, then 2.9, then 2.3 billion. Anglo American is now discussing its sale at around one billion ; nothing has been signed to date. The only well-kept trajectory is the seller's, and it points down.
1 October 2025 : colour and clarity grading is replaced by two designations.
In 1947, Frances Gerety wrote for De Beers, at the N. W. Ayer agency, four words that would hold for three generations. No object in this series has received a story so well built, or so long maintained.
It still holds ; it has merely stopped selecting. In 2025, 61 % of the American couples surveyed chose the stone that story excluded, and De Beers wrote in July 2026 that the growing price gap should help consumers understand that these are « two separate product categories ». The story has outlived the object it pointed to.
This is the only difference between the two stones : the date and the place where the carbon crystallised. It is neither visible, nor weighable, nor measurable with a loupe. It is established in a laboratory, by dedicated instruments, and attested by a document.
The price gap between the two stones measures no property of the stone : it measures what a proof of precedence is worth.
Weak scarcity on both sides, one organised by supply, the other non-existent ; transmission real but undocumented ; a magnificent story, which has stopped sorting. Of the four axes, only one carries the price gap, and it is the one the stone does not show.
That is also, exactly, what DfinA Vault does to a file : say nothing of its content, and everything of its precedence. What is paid for here is not a material, it is a date one can hold up.