Are Lab-Grown Diamonds Real?

Yes. Lab-grown diamonds are real diamonds. They are not imitations, simulants, or synthetic alternatives. They are genuine diamonds — chemically, physically, and optically identical to diamonds formed underground over billions of years. The only difference is their origin: one is created in a laboratory over weeks, the other forms naturally in the earth's mantle.

In 2018, the United States Federal Trade Commission updated its definition of "diamond" to include lab-grown stones, confirming they meet the scientific criteria for the term. Major gemological laboratories, including GIA and IGI, certify them using the same grading standards applied to mined diamonds.

Two methods produce gem-quality lab-grown diamonds. High Pressure High Temperature (HPHT) replicates the extreme conditions deep within the earth — around 1,500 degrees Celsius and pressure exceeding 1.5 million pounds per square inch. A small diamond seed is placed in a carbon source, and the surrounding environment forces carbon atoms to crystallise around it.

Chemical Vapour Deposition (CVD) takes a different approach. A diamond seed is placed in a sealed chamber filled with carbon-rich gas, typically methane. The gas is heated until carbon atoms separate and deposit onto the seed, layer by layer, building a diamond crystal over several weeks. Both methods produce diamonds that are indistinguishable from mined stones without specialised laboratory equipment.

Lab-grown diamonds share every measurable property with mined diamonds. Their chemical composition is pure carbon arranged in a cubic crystal lattice. They rank 10 on the Mohs hardness scale — the hardest known natural material. Their refractive index is 2.42, producing the same brilliance and fire. Their thermal conductivity is identical, which is why standard diamond testers confirm them as real diamonds.

This is what distinguishes lab-grown diamonds from simulants like moissanite or cubic zirconia. Simulants may look similar but have different chemical structures, hardness levels, and optical properties. A lab-grown diamond is a diamond in every scientific sense.

Lab-grown diamonds are graded by the same independent laboratories that certify mined diamonds. GIA, IGI, and other reputable labs assess each stone on the same 4Cs — cut, colour, clarity, and carat weight. The certificate will note that the diamond is laboratory-grown, but the grading criteria remain identical.

A certified lab-grown diamond gives you the same confidence in quality as a certified mined diamond. You know exactly what you are buying — the grade has been independently verified under controlled conditions by trained gemologists. Learn more about what to look for in our diamond certification guide.

Lab-grown diamonds typically cost 60 to 80 percent less than mined diamonds of equivalent quality. This price difference reflects supply economics, not any difference in the stone itself. The diamond you wear looks, feels, and tests the same — it simply costs less because the production process is more efficient.

For a deeper look at whether the value proposition makes sense for your situation, read our guide on whether lab-grown diamonds are worth it.

All LILY DIA engagement rings are available with certified lab-grown diamonds. Every stone comes with an independent grading report so you can see exactly what you are getting.