Lab-Grown Diamonds · Complete Guide

Lab-Grown Diamonds: The Complete Guide (2026)

By Tushar Leclerc · 14 min read

Last Updated: September 3, 2026

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For decades the diamond trade told one story: value equals rarity, and rarity means mined. That story is being rewritten, because a stone grown in a reactor is chemically the same diamond at a fraction of the price. This guide covers what a lab-grown diamond actually is, how it is made, what it costs, and how to choose one, without the sales gloss.

What is a lab-grown diamond?

A lab-grown diamond is a real diamond, pure crystalline carbon, grown in a controlled chamber instead of underground. Same hardness of 10 on the Mohs scale, same refractive index of 2.417, same fire and sparkle. The only difference is where the carbon crystallised.

You will see the same stone called a lab-created diamond, a lab-made diamond, a cultured diamond, or simply a lab diamond. All of those mean the identical thing. The one term worth retiring is "synthetic," which the FTC discourages because it wrongly implies a fake; a lab-grown diamond is not a substitute for a diamond, it is a diamond.

The distinction that does matter is against simulants. Moissanite and cubic zirconia are different materials that imitate the look of a diamond. A lab-grown diamond is not an imitation. Our guide to diamond simulants covers that difference in full.

Are lab-grown diamonds real?

Yes, and the answer is not a matter of opinion. To be a diamond, a stone must be pure carbon arranged in the cubic crystal lattice called diamond cubic. A mined diamond forms that structure over billions of years in the earth's mantle; a lab-grown diamond forms the identical structure in a chamber over a few weeks. Same atoms, same bonds, same lattice.

The FTC confirmed in 2018 that a diamond does not have to be mined to be a diamond, and both IGI and GIA grade lab-grown diamonds on the same 4Cs, cut, colour, clarity and carat, that they apply to mined stones. Set a lab-grown and a mined diamond of matching grades side by side and no gemologist can tell them apart by eye, loupe or standard instrument; only specialist equipment reading trace growth features can separate the two.

Round SolitaireFrom $1,288 Oval HaloFrom $1,530 Cushion SolitaireFrom $1,369 Emerald SolitaireFrom $1,369 Oval Three-StoneFrom $1,450

How they are made: CVD vs HPHT

Two methods grow gem-quality diamonds, both starting from a diamond seed. HPHT (high pressure, high temperature) recreates the earth's mantle, squeezing solid carbon under a press until it crystallises onto the seed. CVD (chemical vapour deposition) grows the crystal layer by layer from a carbon-rich gas in a vacuum chamber. Neither is better for quality, both produce genuine certifiable diamonds, and every IGI report names which method made your stone.

For the full step-by-step of both processes, how long growth takes, and how the rough becomes a finished gem, see our dedicated guide: how are lab-grown diamonds made.

How to choose a lab-grown diamond ring

With a lab-grown diamond the budget stretches far enough that the usual advice changes. Here is the order that matters.

• Shape first. It is the most visible and personal choice. Round is the brightest and most classic; oval and elongated cuts flatter the finger; emerald and asscher read architectural and calm.
• Cut grade over carat. Cut controls sparkle more than any other C. A well-cut 1.5ct outshines a poorly cut 2ct every time, so never drop below Very Good, and prefer Excellent.
• Buy colour and clarity to "eye-clean," not to the top. G to I looks white face-up in most settings; VS1 to VS2 is invisible without magnification. Paying for D/flawless is paying for a certificate, not a visible difference.
• Then metal and setting. 14K is the durable everyday default; our karat guide covers the trade-offs. Solitaire, halo, three-stone and pavé each change how big and how bright the stone reads.
• Insist on the certificate. Never buy a lab-grown diamond without an IGI or GIA report; the girdle inscription lets you verify it independently online.

Get the size right before ordering with our ring size guide, and if you have a specific vision, our custom design studio builds from a sketch.

Mined vs lab-grown vs moissanite

The three stones people weigh against each other. The first two are diamonds; the third is a simulant.

Moissanite is a fine stone sold honestly, but it is not a diamond and throws noticeably more coloured fire. A lab-grown diamond keeps every property of a mined stone; the lab-grown versus natural comparison goes deeper on the first two columns.

What lab-grown diamonds cost

The honest headline: a lab-grown stone lands well below a mined diamond of matching cut, colour and clarity, and the gap widens as carat climbs, because mined prices rise steeply with size while lab-grown prices rise closer to linearly. A 2-carat lab-grown engagement ring starts at $1,288 here; the wider collection opens lower for smaller centre stones.

Beyond carat, four things move the price:

• Cut grade, the one worth paying up for, since it drives sparkle.
• Colour, G to I looks white for much less than D to F.
• Clarity, eye-clean VS1 to VS2 beats paying for flawless.
• Shape, rounds cost more per carat than ovals, cushions or emeralds, because more rough is lost in cutting.

Do they hold value?

Honestly, not well, and neither do mined diamonds. Retail markup means almost any diamond resells for a fraction of its purchase price, and lab-grown resale has softened further as production scaled. Anyone calling a diamond an investment is selling you something. Buy the stone for how it looks and what it marks; that is the return.

One thing it does do reliably: a lab-grown diamond reads as diamond on a thermal tester, because it is diamond. Only laboratory equipment can tell lab-grown from mined, which is exactly what the IGI report is for.

Round SolitaireFrom $1,288 Oval HaloFrom $1,530 Cushion SolitaireFrom $1,369 Emerald SolitaireFrom $1,369 Oval Three-StoneFrom $1,450

Frequently asked questions