What Are Lab-Grown Diamonds? Everything You Need to Know

Published April 19, 2026 · 9 min read

Lab-grown diamonds have moved from a whispered industry secret to the mainstream choice for savvy jewellery buyers. In 2026, they account for a rapidly growing share of the global diamond market, and for good reason: they are chemically, physically, and optically identical to mined diamonds — at a fraction of the cost and with none of the environmental baggage.

But questions remain. Are lab-grown diamonds real? How exactly are they made? And should you buy one? This comprehensive guide answers every question you might have.

Are Lab-Grown Diamonds Real Diamonds?

Yes, unequivocally. Lab-grown diamonds are real diamonds. They share the exact same crystal structure (pure carbon arranged in a cubic lattice), hardness (10 on the Mohs scale), refractive index, and thermal conductivity as mined diamonds. The Federal Trade Commission (FTC) recognises them as diamonds. The only difference is their origin — a laboratory instead of deep within the Earth.

Even trained gemologists cannot distinguish a lab-grown diamond from a natural one using standard tools. Specialised equipment that detects trace nitrogen patterns or growth markers is required to tell them apart. When set in a ring on your finger, they are indistinguishable.

How Are Lab-Grown Diamonds Made?

There are two primary methods used to grow diamonds in a laboratory. Both replicate the natural conditions under which diamonds form — extreme heat and pressure — but compress billions of years into a matter of weeks.

CVD (Chemical Vapour Deposition)

A thin diamond seed is placed in a sealed chamber filled with carbon-rich gas (typically methane). The chamber is heated to around 800–1,200°C, ionising the gas into plasma. Carbon atoms rain down onto the seed, bonding layer by layer to grow a rough diamond crystal.

Growth time: 2–4 weeks for a 1-carat rough
Strengths: Produces very high-purity Type IIa diamonds
Common for: Colourless and near-colourless grades

HPHT (High Pressure, High Temperature)

A diamond seed is placed in a press that generates pressures of roughly 5–6 GPa and temperatures above 1,400°C, mimicking the conditions 150 km below the Earth’s surface. A carbon source (usually graphite) dissolves in a molten metal catalyst and crystallises onto the seed.

Growth time: Several days to weeks
Strengths: Well-established, cost-effective method
Common for: Larger stones and fancy colours