How Lab Grown Diamonds Are Made

Two proven technologies — HPHT and CVD — recreate the conditions that form diamonds in nature, in weeks instead of millions of years.

Recreating Nature

Natural diamonds form when carbon deep inside the earth is put under enormous heat and pressure. Scientists recreate this in two ways: HPHT, which copies the earth's heat and pressure, and CVD, which builds a diamond atom by atom from a carbon-rich gas. Both start from a tiny diamond "seed" and both produce real diamonds.

A Short History

Year	Milestone
1797	Chemist Smithson Tennant proves diamond is made of pure carbon.
1954	Researchers at General Electric produce the first reproducible lab-made diamonds using high pressure and high temperature.
1980s–1990s	CVD techniques mature, and lab diamonds move from industrial use toward gem quality.
2018	The U.S. FTC updates its definition of "diamond" to include laboratory-grown stones.
Today	Gem-quality lab grown diamonds are widely available and graded by labs such as IGI.

Method 1: HPHT (High Pressure, High Temperature)

Seed: a small diamond seed is placed in a growth cell with a pure carbon source and a metal solvent.
Pressure & heat: a large press creates extreme pressure (tens of thousands of atmospheres) and heat of roughly 1,300–1,600°C.
Growth: the carbon dissolves and crystallises onto the seed, growing a rough diamond.
Cooling: the diamond is slowly cooled and removed, ready to be cut.

Method 2: CVD (Chemical Vapor Deposition)

Seed: thin diamond seed plates are placed in a sealed vacuum chamber.
Gas: a carbon-rich gas (usually methane) and hydrogen are introduced.
Plasma: microwave energy heats the gas into a glowing plasma at around 700–1,200°C, breaking the gas molecules apart.
Layer by layer: carbon atoms settle on the seed and build the diamond crystal one layer at a time over several weeks.

HPHT vs CVD at a Glance

	HPHT	CVD
How it works	Heat + pressure, like the earth	Carbon gas deposited in a vacuum
Temperature	≈ 1,300–1,600°C	≈ 700–1,200°C
Pressure	Very high	Very low (vacuum)
Growth time	Days to a few weeks	Several weeks
Result	Real diamond	Real diamond

Neither method is "better" — the quality of the finished diamond depends on the grower and on how it is cut and graded. That is why the IGI certificate, not the growth method, is what to check.

From Rough Diamond to Your Ring

Planning: each rough crystal is mapped to get the best shape and sparkle from it.
Cutting & polishing: master cutters shape the facets — the same craft used for mined diamonds.
Independent grading: the finished stone is graded by IGI for the 4Cs and confirmed as lab grown.
Handcrafted setting: our artisans set it into your chosen gold or platinum ring, made to order.

Frequently Asked Questions

How long does it take to grow a diamond?

Typically from a few days to several weeks, depending on the method and the size of the stone.

Is an HPHT or CVD diamond better?

Both produce real diamonds. Quality depends on the individual stone — check its IGI grades rather than the method.

Are lab grown diamonds 100% carbon?

Yes, like mined diamonds they are crystallised carbon, with tiny trace elements that labs use to identify them.

Are lab grown diamonds treated?

Some lab grown diamonds receive a post-growth treatment to improve colour. Reputable labs like IGI note this on the certificate.

How do I care for a lab grown diamond?

Exactly like any diamond: clean it with warm water, mild soap and a soft brush, and store it separately to avoid scratching other jewellery.

Ready to Find Your Ring?

Explore IGI-certified lab grown diamonds and brilliant moissanite, handmade to order in 925 silver, 10K/14K/18K solid gold or 950 platinum.

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Continue learning:
The 4Cs of Diamonds →Diamond Shapes Guide →What Are Lab Grown Diamonds? →Lab Grown vs Mined Diamonds →Moissanite vs Lab Grown Diamonds →