Lab grown diamonds are real diamonds. They share the same chemical composition, crystal structure, and optical properties as natural diamonds. The difference lies in origin: one formed deep within the Earth over geological time, the other is grown under controlled laboratory conditions using advanced technology.

This guide explains how lab grown diamonds developed from early scientific experiments into gem-quality stones, how the two main growth methods work, how long high-quality diamonds typically take to produce, and what buyers should understand when comparing lab grown and natural diamonds today.

From laboratory experiments to gem-quality diamonds

The concept of growing diamonds in a laboratory is not new. High Pressure High Temperature (HPHT) synthesis was first achieved in the 1950s, most notably by researchers at General Electric in the United States. These early diamonds were created for industrial and scientific applications and were generally too small, opaque, or structurally imperfect to be used as gemstones.

A significant milestone came in the early 1970s, when researchers at General Electric successfully produced the first gem-quality HPHT diamonds. These stones were large and transparent enough to be examined by gemological laboratories and considered suitable for cutting and polishing. This marked the transition from purely industrial synthetic diamonds to diamonds that could enter the gem trade.

Even then, production was limited. Consistent growth of large, clean crystals suitable for jewellery remained technically challenging for decades.

What changed was not the basic principle of diamond growth, but the precision and control of the growth environment.

From the 1990s onward, advances in pressure systems, temperature stability, carbon chemistry, and crystal lattice control enabled the production of larger, optically transparent single crystals. Over time, improvements in impurity management, particularly nitrogen and boron control, allowed for better colour outcomes and higher clarity.

According to the International Gemological Institute (IGI), modern laboratory-grown diamonds are now produced at a quality and scale that allows them to be graded, certified, and traded using the same gemological frameworks applied to natural diamonds.

The two primary growth methods

Today, lab grown diamonds are produced using two established methods: HPHT and CVD. Both can yield high-quality gemstones when executed properly.

HPHT: High Pressure High Temperature

HPHT replicates some of the conditions under which natural diamonds form in the Earth’s mantle. A small diamond seed is placed in a press with a carbon source. Under extreme pressure and high temperature, carbon atoms dissolve and crystallize onto the seed, growing a diamond crystal.

HPHT is historically the earliest method used for gem-quality production and remains widely used today.

Advantages

• Capable of producing high-quality, well-structured crystals
• Effective for certain colour outcomes depending on growth and treatment
• Mature, well-understood technology at scale

Considerations

• Some HPHT diamonds may undergo post-growth treatment to improve colour
• Growth-related characteristics require professional assessment and transparent disclosure on grading reports

CVD: Chemical Vapor Deposition

CVD grows diamonds in a vacuum chamber rather than under extreme pressure. A diamond seed is exposed to a carbon-rich gas that is activated into plasma. Carbon atoms deposit onto the seed layer by layer, forming a diamond crystal over time.

CVD has become increasingly prominent as technology has improved and scaled.

Advantages

• Layer-by-layer growth allows precise control of crystal development
• Widely used for producing near-colourless and colourless diamonds
• Growth characteristics are well documented by gemological laboratories

Considerations

• As-grown CVD diamonds may show colour tints that are later corrected through post-growth treatment
• Final quality depends heavily on process control and finishing, not the method alone

Where lab grown diamonds are produced

Lab grown diamond production is global. Historically, China has played a major role in high-volume production, alongside earlier research and production in the US and Russia. India has become increasingly important as a centre for cutting, polishing, and scaling lab grown diamond manufacturing.

For buyers, the country of production is less important than:

• Independent certification
• Disclosure of growth method and treatments
• The actual appearance and proportions of the finished diamond

How long does it take to grow a high-quality lab diamond?

There is no single fixed timeline. Production time depends on:

• Growth method (HPHT or CVD)
• Target rough size and shape
• Desired colour and clarity
• Growth rate stability
• Post-growth treatment requirements
• Cutting and polishing yield

In general, the growth phase of a gem-quality lab diamond is measured in weeks to months, not days. Larger stones require longer and more carefully controlled growth. Once the diamond rough has been grown, it follows the same downstream process as a natural diamond. Cutting, polishing, quality control, and independent certification are carried out using the same techniques and standards applied to mined diamonds. Depending on the size of the rough and the chosen cut, the cutting and polishing alone can take several weeks to complete.

For a polished stone such as a 2.00 carat F colour, VVS2 clarity round diamond, production typically involves:

• Weeks  of controlled crystal growth
• Additional time for cutting and polishing
• Independent grading by a laboratory such as IGI or GIA

Any claim of a single universal production time for all diamonds of a given size should be treated as marketing, not manufacturing reality.

Can lab grown and natural diamonds be distinguished by eye?

No. A lab grown diamond can look identical to a natural diamond.

Even under a microscope, visual observation alone is not considered a reliable method for determining origin. While trained gemologists may observe growth-related features that suggest laboratory growth, definitive identification relies on advanced analytical techniques and laboratory instrumentation.

This is why independent grading reports are essential. Reputable laboratories clearly state whether a diamond is natural or laboratory-grown and disclose any treatments applied.

How identification and grading work today

As lab grown diamond quality has improved, identification has become more dependent on:

• Spectroscopy
• Advanced imaging
• Laboratory-level analysis

The International Gemological Institute grades lab grown diamonds using the same core principles applied to natural diamonds, while clearly disclosing growth method, origin, and any post-growth treatment on the report.

For buyers, the certificate is not just paperwork. It is the primary tool for understanding what you are purchasing.

What to check before buying a lab grown diamond

1. An independent grading report from IGI or GIA
2. Clear disclosure of growth method and treatments
3. Full measurements and proportions, not just headline grades
4. Video or imagery of the actual diamond
5. A seller with transparent policies and EU-compliant service

Summary

• Lab grown diamonds are real diamonds with the same physical and optical properties as natural diamonds
• The first gem-quality HPHT diamonds were produced in the early 1970s by General Electric in the USA
• Modern gem-quality production became scalable from the 1990s onward
• The two main growth methods are HPHT and CVD
• Growth takes weeks, with additional time for finishing and certification
• Visual inspection alone cannot reliably determine origin
• Independent certification is essential for informed buying

Understanding the technology and history behind lab grown diamonds allows buyers to focus on what truly matters: quality, transparency, and suitability for their needs.

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Frequently asked questions

1. Are lab grown diamonds real diamonds?
Yes. Lab grown diamonds have the same chemical composition, crystal structure, and optical properties as natural diamonds. The difference is their origin, not their material.

2. Can you tell a lab grown diamond from a natural diamond by eye?
No. Lab grown diamonds can look identical to natural diamonds. Visual inspection alone, even under a microscope, is not considered a reliable way to determine origin.

3. What is the difference between HPHT and CVD lab grown diamonds?
HPHT grows diamonds under high pressure and temperature, while CVD grows diamonds layer by layer in a controlled chamber. Both methods can produce high-quality gem diamonds when properly executed and certified.

4. Will my lab grown diamond change color over time?
No. A lab grown diamond does not change color over time under normal wear. Diamond is a stable crystal structure. Any color present is inherent to the diamond at the time it is grown and graded. If a diamond has undergone post-growth treatment, this is disclosed on the grading report and does not affect everyday durability or appearance.

5. Is HPHT quality worse than CVD diamonds?
No. HPHT diamonds are not inherently worse than CVD diamonds. Both growth methods can produce high-quality gem diamonds. Final quality depends on growth control, post-growth treatment, and cutting, not the method itself. Well-grown HPHT and CVD diamonds can both achieve excellent color and clarity grades when properly certified.

6. How long do lab grown diamonds last?
Lab grown diamonds last indefinitely. They have the same hardness, durability, and resistance to wear as natural diamonds. Under normal use, a lab grown diamond will last for generations, just like a natural diamond.