What Is a CVD Diamond? How They're Made, CVD vs HPHT, and What They Cost

A CVD diamond is a laboratory-grown diamond produced by Chemical Vapour Deposition, a process in which carbon-rich gas is broken down inside a vacuum chamber and carbon atoms settle layer by layer onto a diamond seed. The resulting stone is chemically, physically and optically identical to a mined diamond. CVD is one of two commercial growing methods; the other is HPHT.

What does CVD stand for?

CVD stands for Chemical Vapour Deposition. It describes how the diamond was grown, not its quality. A CVD diamond can fall anywhere on the colour and clarity scales, so the growth method alone tells you nothing about whether a stone is good. An IGI or SGL certificate states the growth method alongside the 4Cs.

Are CVD diamonds real diamonds?

Yes. A CVD diamond has the same carbon crystal structure as a mined diamond and rates 10 on the Mohs hardness scale, the same as any other diamond. It is not a simulant. Cubic zirconia and moissanite are different materials that imitate the look of diamond; a CVD diamond is diamond.

Gemological laboratories can distinguish lab grown from mined stones by examining growth patterns and trace elements, which is why every stone is certified. The distinction is origin, not composition.

How is a CVD diamond made?

The process takes several weeks and runs in four stages.

1. Seed placement. A thin slice of existing diamond is placed in a vacuum chamber. It acts as the template the new crystal grows on.
2. Gas introduction. Carbon-rich gas, typically methane mixed with hydrogen, is pumped into the chamber.
3. Plasma generation. Microwave energy heats the gas until it ionises into plasma, breaking the molecules apart and freeing carbon atoms.
4. Deposition. The freed carbon atoms settle onto the seed and bond to its crystal lattice, building the diamond layer by layer. The rough crystal is then cut and polished like any other diamond.

What is the difference between CVD and HPHT diamonds?

CVD grows a diamond from carbon gas at relatively low pressure. HPHT, or High Pressure High Temperature, recreates the extreme heat and pressure found deep in the earth, using a metal flux to dissolve carbon and crystallise it onto a seed.

Both produce genuine diamonds. CVD accounts for the majority of gem-quality lab grown diamonds produced in India and is generally favoured for larger, higher-clarity stones. HPHT is often used for smaller stones and for treating existing diamonds to improve colour.

Neither method is inherently superior. The grading on the certificate matters far more than the method used to grow the stone.

What is a Type IIa diamond?

Type IIa describes a diamond containing almost no nitrogen impurities, which is the chemical classification associated with the highest colour purity. Only a small minority of mined diamonds are Type IIa, whereas a high proportion of CVD diamonds fall into this category because the growth environment is controlled.

This is a genuine technical advantage of the method, though it does not guarantee a high grade on its own. Cut quality still determines how a stone actually looks.

How much does a CVD diamond cost in India?

A lab grown diamond costs substantially less than a mined diamond of comparable carat weight, colour and clarity. The saving is large enough that most buyers move up one or two carat weights rather than spend less.

At Ivana Jewels, finished jewellery prices are recalculated daily against the prevailing gold rate, because gold accounts for a significant share of the cost of a finished piece. That means the figure on a product page is the current one rather than a fixed list price. For a breakdown by carat weight, see our lab grown diamond price guide for India.

Do CVD diamonds hold their value?

This is where honesty serves buyers better than sales copy. Lab grown diamonds, CVD included, have limited resale value on the open second-hand market. That is true of most jewellery once retail margin is stripped out, mined diamonds included, but the gap is wider for lab grown stones because supply is not constrained.

The practical route to recovering value is a retailer scheme rather than a private sale. Ivana Jewels offers a lifetime buyback at 80% of the prevailing diamond value and 100% of the prevailing gold value at the time of buyback, with making charges, discounts and GST deducted. Full terms are on our All Policies page.

If value retention is your primary goal, gold is the better instrument. If you want the largest, cleanest stone your budget allows, a CVD diamond is the better one.

What are the genuine limitations of CVD diamonds?

Three worth knowing before you buy.

• Resale is limited. Covered above. Buy for wear, not as an investment.
• Some CVD stones receive post-growth treatment to improve colour. This is disclosed on the certificate, which is one reason to read it rather than take a verbal assurance.
• Certification consistency varies by retailer. Some brands certify every stone; others certify only above a carat threshold. Ask which laboratory certified your specific piece, and for stones above a carat, ask for the certificate before paying.

How to check a CVD diamond before buying

• Ask which laboratory issued the certificate. Ivana Jewels uses IGI or SGL on every stone.
• Check that the certificate number is laser-inscribed on the girdle, and that it matches the paperwork.
• Confirm the growth method is stated on the certificate.
• Check the gold is BIS hallmarked, and note the karat: 14kt is harder and better for daily wear, 18kt has a richer colour.
• Ask for the buyback and exchange terms in writing before purchase, not after.

Frequently asked questions

Is a CVD diamond better than a natural diamond?

Neither is better; they are the same material grown differently. A CVD diamond will give you a larger or cleaner stone for the same budget. A mined diamond will retain marginally more resale value. Choose based on which of those matters more to you.

How long do CVD diamonds last?

Indefinitely. At 10 on the Mohs scale, a CVD diamond is as hard as any other diamond and will not scratch, cloud or fade with wear. Settings wear before stones do, which is why prongs should be checked every year or two.

Can a jeweller tell the difference between CVD and mined?

Not by eye, and not with a standard loupe. Distinguishing them requires specialist laboratory equipment that examines growth patterns and fluorescence. This is precisely why independent certification exists.

Which is better, CVD or HPHT?

Neither. Judge the stone by its certificate, not its growth method. A well-cut HPHT stone with a good grade will outperform a poorly cut CVD stone every time.

Are CVD diamonds certified?

They should be. Every lab grown diamond sold by Ivana Jewels is certified by IGI or SGL, and the certificate records carat weight, colour, clarity, cut and the growth method. If a retailer cannot produce a certificate for a stone, that is the point to walk away.

Browse lab grown diamond rings, earrings and pendants, or visit one of our eleven showrooms in Delhi, Mumbai, Ahmedabad, Surat, Pune, Thane, Nagpur, Noida, Hyderabad and Mohali, open 10:30am to 9pm every day.