From secret crystals to existential threat: 72 years of lab-grown diamonds

Key milestones in lab-grown diamond technology and commercialisation, February 1953 – June 2025

Laboratory origins

16 February 1953

Project Quintus: the world's first synthetic diamonds, grown in secret

ASEA's team in Stockholm produces roughly 40 tiny diamond crystals — each just 0.1 mm across — using a split-sphere HPHT apparatus designed by Baltzar von Platen at 8.4 GPa and 2,200°C. Diamond identity is confirmed by X-ray at Stockholm University. The result remains classified for three decades.

8 December 1954

GE's Experiment 151: first synthesis at Schenectady

Herbert Strong sets his pressure-cone apparatus to ~50,000 atmospheres and 1,250°C, mixing carbon and iron with two natural diamond seed crystals — General Electric's first confirmed diamond synthesis, though not yet reproducible at scale.

16 December 1954

Tracy Hall's belt press makes synthesis commercially reproducible

Hall's purpose-built "belt" press exceeds 100,000 atmospheres and 1,600°C, yielding the first witnessed synthesis a second team could reliably replicate. GE announces the breakthrough publicly on 15 February 1955 — the moment synthetic diamonds enter the scientific record.

Towards gem quality

1971

GE grows the first gem-quality lab-grown diamonds

GE researchers produce crystals large and clear enough for potential jewellery use — the first time synthetic diamonds cross the gem threshold. GIA scientists publish the first peer-reviewed study of lab-grown diamonds the same year, establishing a formal scientific record.

Mid-1980s

Commercial gem-quality crystals reach the market; CVD refined

Manufacturers bring gem-quality HPHT crystals to market in commercial quantities for the first time — initially small and off-colour, but improving. Chemical Vapor Deposition (CVD), a lower-pressure alternative growth method, is simultaneously refined for consistent gem-quality output.

2007

GIA issues its first grading reports for lab-grown diamonds

The world's leading gem-grading authority begins formally assessing lab-grown stones using the same 4Cs framework applied to natural diamonds, lending synthetic gems a standardised credibility that paves the way for retail adoption.

Commercial disruption

2010s

US, Indian and Chinese start-ups perfect mass production of jewellery-quality stones

Both HPHT and CVD processes are scaled for the first time to produce full jewellery-quality stones reliably and cheaply. Before 2010, most synthetic diamonds were smaller than half a carat; by the mid-2010s they rivalled the best natural stones in clarity and colour.

29 May 2018 — announced; September 2018 — sales launch

De Beers disrupts the LGD sector with Lightbox

De Beers announces Lightbox Jewellery — the first brand to sell lab-grown diamonds at a flat $800 per carat regardless of colour (white, pink or blue). The fixed-price model upends the convention of pegging LGD prices to discounted natural stone equivalents, reshaping the entire sector's pricing logic.

18 June 2025

The Luanda Accord: producing nations mobilise to defend natural diamonds

Angola, Botswana, the DRC and Namibia sign a landmark agreement in Luanda, pledging the equivalent of 1% of each signatory's annual rough diamond revenues to the Natural Diamond Council for a global campaign promoting natural diamonds over lab-grown alternatives — the industry's first coordinated defensive response in decades.

Synthetic diamonds progressed from 40 secret, microscopic crystals grown in Stockholm in 1953 to commercially existential competitors within a single human lifetime. The Luanda Accord — signed exactly 72 years later and pledging 1% of rough revenues to generic marketing — is the natural diamond industry's first coordinated defence since De Beers discontinued its "A Diamond Is Forever" campaign, itself a measure of how rapidly the disruption has accelerated.