What Is a Lab Grown Diamond? Meaning, Process, Price & Certification

A lab grown diamond is a real diamond, not an imitation, grown inside a controlled laboratory instead of being mined from the earth. It has the same crystal structure, hardness, and brilliance as a natural diamond because it is made of the exact same material: pure carbon. Scientists grow it using two proven methods, HPHT and CVD, over a few weeks to a couple of months, and it typically costs 60 to 75 percent less than a natural diamond of comparable size and quality. Trusted gem labs such as IGI test and certify every genuine stone, and the report always states its lab-grown origin.

Quick Summary: Lab Grown Diamonds at a Glance

What Does “Lab Grown Diamond” Actually Mean?

The term lab grown diamond simply describes where the stone comes from, not what it is made of. Chemically, optically, and physically, it is identical to a natural diamond.

The only real difference is origin. One forms in a lab under controlled conditions. The other forms inside the earth over billions of years. This is why regulatory bodies and Indian jewellery associations classify it as a genuine diamond, not an imitation like cubic zirconia or moissanite. India even has a formal legal definition now: the Bureau of Indian Standards issued IS 19469:2025, effective January 2026, which sets out standardised terminology to distinguish natural diamonds from laboratory-grown ones in trade documentation.

How Are Lab Grown Diamonds Made? HPHT vs CVD

Lab grown diamonds are created using two main methods: HPHT and CVD. Both recreate the conditions carbon needs to crystallise into a diamond, just inside a machine instead of underground.

HPHT: High Pressure High Temperature

HPHT was the first method used to grow gem-quality diamonds, developed in the 1950s. A small diamond seed is placed with a carbon source inside a press. The chamber is heated to roughly 1,300–1,600°C under extremely high pressure, similar to conditions deep in the earth's mantle. Carbon dissolves under this pressure and crystallises around the seed to form a new diamond, usually within a few weeks.

CVD: Chemical Vapour Deposition

CVD is the newer, more widely used method today. A diamond seed sits inside a vacuum chamber filled with carbon-rich gases such as methane and hydrogen. Energy breaks the gas down, and carbon atoms settle on the seed layer by layer over several weeks. Most Indian manufacturers, especially in Surat, rely on this method to grow lab created diamonds, often followed by an HPHT treatment step to remove any brownish tint.

Is a Lab Grown Diamond a Real Diamond?

Yes. A lab grown diamond passes every physical and chemical test that defines a diamond. It scores 10 on the Mohs hardness scale, shows the same refractive index, and delivers the same fire and brilliance as a mined stone. Even trained gemologists cannot spot the difference with the naked eye - only advanced lab equipment, such as spectroscopy, can identify its growth origin.

Lab Grown Diamond vs Natural Diamond: Key Differences

The stones look and perform the same, but a few practical differences matter for buyers:

Lab Grown Diamond Price in India: Why It Costs Less

A lab grown diamond costs less mainly because it skips the decades-long mining, exploration, and extraction process behind a natural stone. Growing a diamond in a lab takes weeks, not millions of years, and that brings production costs down sharply.

This price gap makes bigger, higher-clarity stones affordable for far more Indian buyers, whether the choice is a solitaire pendant or a full engagement ring. The exact price still depends on carat, cut, colour, and clarity, so comparing certified stones from a transparent seller is the only fair way to judge value.

Why India Has Become the World's Lab Grown Diamond Hub

India, particularly Surat in Gujarat, is the world's largest processing centre for lab grown diamonds. According to Gem & Jewellery Export Promotion Council (GJEPC) trade data reported in mid-2026, India's polished lab-grown diamond exports reached about 18.8 million carats in FY2025-26, overtaking polished natural diamond exports at roughly 16 million carats - a first for the industry, with lab-grown shipments individually outpacing natural ones in both March and April 2026.

GJEPC data also indicates that lab-grown diamond manufacturing adds 17 to 18 percent value within India's processing chain, compared to just 3 to 5 percent for cutting and polishing natural diamonds. This is one reason thousands of skilled diamond cutters in Surat have shifted toward CVD and HPHT production in recent years.

Are Lab Grown Diamonds Certified? Understanding IGI and GIA Reports

Yes, a genuine lab grown diamond always comes with a certification report - but the two leading labs no longer grade it the same way, and this is worth knowing before you buy.

IGI (International Gemological Institute): still grades lab grown diamonds on the full 4Cs scale used for natural diamonds - cut, colour, clarity, and carat - with detailed reports. IGI remains the most widely used lab for lab-grown certification in India, including at retailers such as Goenka Jewellers.

GIA (Gemological Institute of America): changed its approach from October 1, 2025. GIA no longer issues detailed 4Cs grades for lab-grown diamonds; instead, it classifies each stone as “Premium” or “Standard” based on an overall assessment of colour, clarity, and cut, and does not grade stones that fall below its Standard threshold. GIA still applies the full 4Cs system to natural diamonds.

Whichever lab issues the report, it will clearly state “laboratory-grown” on the certificate, so there is no confusion for the buyer. Always ask for this certificate before buying, whether shopping online or in a store, and check which grading system was used so you can compare stones on equal terms.

Is Buying a Lab Grown Diamond a Good Decision?

For most buyers in India today, a lab grown diamond makes practical sense. It offers the same brilliance and durability as a natural diamond at a noticeably lower price, letting buyers choose a bigger stone or better clarity within budget. It also appeals to buyers who prefer a lower environmental footprint.

The one trade-off is resale value, since natural diamonds still command a stronger secondary market. If the stone is meant to be worn and loved rather than resold, a lab grown diamond is a smart, well-informed choice.

How to Buy a Genuine Lab Grown Diamond in India

Before buying, check three things: a valid IGI or GIA certificate, the seller's grading transparency, and after-sales support such as exchange or buyback policies.

Established Indian jewellers such as Goenka Jewellers offer IGI-certified lab grown diamond rings, earrings, and necklaces along with clear grading reports and a buyback policy, which helps buyers compare quality confidently before purchase. You can also read more in the full guide to lab grown diamonds in India or check the FAQs page for buying and exchange policy details.

Working with a jeweller who explains the 4Cs (or the Premium/Standard assessment, if GIA-graded) and shows the certificate upfront remains the simplest way to avoid overpaying or ending up with an uncertified stone.

Frequently Asked Questions

1. Is a lab grown diamond fake?

No. It is a real diamond made of carbon, grown in a lab instead of mined. It is not an imitation like cubic zirconia.

2. Do lab grown diamonds pass a diamond tester?

Yes. Since they are chemically identical to natural diamonds, they pass the standard diamond testers used in jewellery stores. Distinguishing them from natural diamonds requires specialised lab equipment, not a handheld tester.

3. How long does it take to grow a lab diamond?

Most lab grown diamonds take a few weeks to a couple of months to grow, depending on size and method.

4. Is IGI certification reliable for lab grown diamonds?

Yes. IGI is among the most recognised labs globally for grading and certifying lab grown diamonds, and it continues to issue full 4Cs reports for them.

5. Does GIA still grade lab grown diamonds like natural ones?

No. Since October 2025, GIA has used a simplified “Premium” or “Standard” Quality Assessment for lab-grown diamonds instead of full 4Cs grading. It still applies the traditional 4Cs to natural diamonds.

6. Are lab grown diamonds a good option for engagement rings in India?

Yes. Many Indian buyers now choose lab grown diamonds for engagement rings because they offer bigger, higher-clarity stones within a realistic budget.

Whether you are buying your first diamond or upgrading an old piece, understanding how a lab grown diamond is made, certified, and priced helps you buy with confidence, not guesswork.

Sources & References

●        GIA (Gemological Institute of America) - HPHT and CVD Diamond Growth Processes

●        GJEPC export data, as reported by JCK: India's Lab-Grown Diamond Exports Surpass Naturals by Volume