What Is a CVD Diamond? Chemical Vapor Deposition Explained

Short answer

A CVD diamond is a diamond grown in a laboratory, atom by atom, using a process called Chemical Vapor Deposition. It has the exact same crystal structure, hardness, and chemical composition as a diamond pulled from the ground — the only difference is where it was made. CVD diamonds are graded by the same labs (GIA, IGI) that grade natural diamonds, and every legitimate CVD stone is sold with a certificate that clearly states “laboratory-grown.”

How Chemical Vapor Deposition actually works

1. A seed is placed in a chamber. A thin slice of diamond — natural or lab-grown — is placed in a sealed chamber and acts as the starting point for growth.
2. The chamber is filled with carbon-rich gas. Usually a mix of methane (CH₄) and hydrogen. No high pressure is involved — this is the key difference from HPHT growth.
3. The gas is ionized into plasma. Microwaves, a hot filament, or an electrical arc heat the gas to around 800–1000°C, breaking the methane apart and freeing carbon atoms.
4. Carbon atoms deposit onto the seed, layer by layer. Over several weeks, the loose carbon atoms bond to the seed’s crystal lattice and build up a rough diamond, growing roughly 0.1mm per hour.
5. The rough stone is cut and polished exactly like a natural rough diamond, then sent to a gemological lab for grading.

Because growth happens flat, layer by layer, in a low-pressure environment, CVD diamonds typically start as a tabular (flat) rough crystal — different from the octahedral shape natural diamonds usually form in the earth. This doesn’t affect the finished, cut stone at all; it’s only relevant to how a gemologist can sometimes identify the growth method under lab equipment.

Is a CVD diamond a “real” diamond?

Yes. This is the single most common misconception. A CVD diamond is not a diamond simulant like cubic zirconia or moissanite — those are different materials that only look like diamond. A CVD diamond is diamond: pure crystallized carbon, 10 on the Mohs hardness scale, with the same brilliance, fire, and thermal conductivity as a natural stone. A jeweler’s thermal diamond tester cannot tell a CVD diamond from a natural one — only specialized lab equipment (which checks for growth-pattern fluorescence and trace nitrogen signatures) can.

The US Federal Trade Commission and international grading bodies both classify CVD stones as diamonds, not imitations — they just require the word “laboratory-grown” or “lab-grown” to appear on the certificate and receipt, which is exactly what we do on every CVD piece we sell.

CVD vs mined diamonds: what’s actually different

	Natural diamond	CVD diamond
Composition	Pure carbon	Pure carbon
Hardness	10 Mohs	10 Mohs
Formation time	1–3 billion years, underground	2–4 weeks, in a lab
Optical properties	Identical	Identical
Typical price for the same size/quality	Higher	30–50% lower
Certificate	GIA / IGI, marked “natural”	GIA / IGI, marked “laboratory-grown”

The price gap exists because of scarcity and mining cost, not quality. A well-cut CVD diamond with a strong certificate is not a compromise — it’s simply a diamond made a different way.

CVD vs HPHT: the other lab-growth method

CVD isn’t the only way to grow a diamond. HPHT (High Pressure, High Temperature) recreates the pressure and heat conditions found deep in the earth instead of using a low-pressure gas chamber. Both methods produce genuine diamond; they just get there differently, and each leaves slightly different internal growth signatures that a lab can read. Read our full HPHT explainer for how that process works.

Buying CVD diamonds in Cambodia

At LAAR EK Jewelry (ហាងពេជ្រល្អឯក) in Phnom Penh, every CVD diamond we sell — loose or set — comes with an independent GIA or IGI certificate stating carat, cut, color, clarity, and growth method, so you know exactly what you’re buying and can verify it yourself. We deal in both natural diamonds and CVD/HPHT lab-grown diamonds, wholesale and retail (មានលក់បោះដុំ និងរាយ ពេជ្រសុទ្ធ និង ពេជ្រ CVD/HPHT).

Have a question about a specific stone or want a wholesale quote? Message us on Telegram — we usually reply within the hour during opening times (7:00 AM – 8:30 PM, every day).