How Lab Grown Diamonds Are Made (CVD vs HPHT, Explained Simply)

A lab grown diamond isn't "made to look like" a diamond — it is one, grown using the same recipe nature uses: carbon, heat, and pressure. The lab simply speeds up a process that takes the earth billions of years. There are two ways to do it.

It starts with a seed

Both methods begin with a tiny slice of diamond called a seed. Every diamond grown in a lab is built atom by atom on top of that seed, so the crystal structure is identical to a mined diamond from the very first layer.

Method 1: HPHT (High Pressure, High Temperature)

HPHT recreates the exact conditions deep in the earth. The seed is placed with a source of pure carbon and exposed to temperatures around 1,400°C and enormous pressure — roughly 1.5 million pounds per square inch. The carbon melts and crystallises onto the seed, growing a rough diamond over a few weeks.

HPHT is the older of the two methods and produces excellent, high-quality crystals.

Method 2: CVD (Chemical Vapour Deposition)

CVD is the more modern approach. The seed sits in a sealed chamber filled with a carbon-rich gas (usually methane). The gas is heated until the carbon atoms break free and settle onto the seed, layer by layer, like frost forming on glass. Over several weeks, the diamond grows upward.

CVD offers fine control over quality and is widely used for gem-grade diamonds today.

Then comes the human part

Whichever method grows the rough crystal, the next steps are identical to natural diamonds: the rough is cut and polished by skilled hands, then graded on the 4Cs — cut, colour, clarity, and carat. This is where a diamond earns its sparkle, and where craftsmanship makes all the difference.

Weeks, not billions of years

Start to finish, a gem-quality lab grown diamond takes a few weeks to grow and then cut. That efficiency — not any shortcut in quality — is why lab grown diamonds cost far less than mined stones of the same grade.

Grown and cut under one roof

At Luzora, we don't just source lab grown diamonds — we grow and cut our own. That means we control quality at every stage, from seed to setting, with no middlemen adding cost along the way. Every stone we set is G colour or better, VS clarity or better, and IGI certified.

See what we make — explore Luzora diamonds →