What are lab-grown diamonds? Explaining the differences, pros, and cons compared to natural diamonds

“What’s the difference between lab-grown diamonds and natural ones?”
“Are they real diamonds?”
“Is it okay to choose one for an engagement ring or a treat-yourself piece of jewelry?”
These are the questions everyone faces when first considering lab-grown diamonds.

To give you the conclusion upfront: lab-grown diamonds are real diamonds, identical to natural diamonds. The only difference is where they were “born”; their properties as a gemstone, such as their chemical composition and brilliance, remain unchanged.
However, because there are differences in the production method, rarity, and how they align with personal values, the right choice depends on what you prioritize.

In this article, we will provide a basic overview of lab-grown diamonds, focusing primarily on their differences from natural diamonds.

What is a Lab-Grown Diamond?

A lab-grown diamond is a diamond created in a laboratory or specialized facility. In English, they are called “Lab Grown Diamonds,” and they are sometimes referred to as “cultured diamonds” in Japanese.
They are real diamonds composed primarily of the same carbon as natural diamonds, and are not imitation stones.

While natural diamonds are formed deep underground over an immense period of time, lab-grown diamonds are created by artificially replicating that environment. A key characteristic is that, aside from their place of origin, they are identical to natural diamonds in substance.

Similarities and Differences from Natural Diamonds

Composition and Crystal Structure

Chemically, both lab-grown and natural diamonds are carbon crystals (C). Both have a Mohs hardness of 10; there is no other substance besides diamond that has a Mohs hardness of 10.
The FTC (Federal Trade Commission in the U.S.) states that both natural and lab-grown diamonds should be treated as “diamonds,” and the ISO (International Organization for Standardization) holds a similar view.

Production Method

The biggest difference is the production method. Natural diamonds are formed deep underground under high-temperature and high-pressure conditions over a very long period.
On the other hand, lab-grown diamonds are created in a laboratory using two methods: the “HPHT method,” which technologically replicates that environment, or the “CVD method,” which grows crystals using gas as the raw material.

Grading and Quality Assessment

Lab-grown diamonds are evaluated for quality using the same “4Cs” (Carat, Color, Clarity, and Cut) as natural diamonds.
Note that as of October 2025, the GIA has changed its assessment for lab-grown diamonds to a simplified two-tier category of “Premium” and “Standard,” which differs from the evaluation method for natural diamonds. Conversely, the IGI continues to use the same full 4C evaluation as they do for natural stones. When checking a grading report, please be aware that the granularity of the information varies depending on the issuing organization.

Rarity and Values

Natural diamonds are chosen by those who find value in the rarity and long history created by nature.
In contrast, lab-grown diamonds are considered to align well with values that prioritize quality, rationality, and environmental or ethical considerations.
It is not a matter of which is superior; it is natural to view them as having different appeals depending on what you prioritize.

Differences at a Glance: Comparison Table

Item	Lab-Grown Diamond	Natural Diamond
Composition & Crystal Structure	Carbon crystal (Diamond)	Carbon crystal (Diamond)
Production Method	Artificially created in a lab	Formed naturally underground
Mohs Hardness	10	10
Grading & Quality Assessment	4C standards (GIA uses simplified 2-tier; IGI uses full evaluation)	Full 4C evaluation
Rarity	More accessible than natural	Has rarity created by nature
Aligned Values	Quality, rationality, environmental/ethical concerns	Rarity, traditional value

Who Lab-Grown Diamonds Suit / Who Should Consider Natural Diamonds

Who Lab-Grown Diamonds Suit
・Those who want higher quality or a larger size for the same budget.
・Those who prioritize quality and rationality.
・Those who value environmental and ethical considerations as part of their lifestyle.
・Those looking for real diamond jewelry suitable for everyday wear.

Who Should Consider Natural Diamonds
・Those who find intrinsic value in the fact that it is “natural.”
・Those who are drawn to the rarity created by nature.
・Those whose partner or family places high importance on a stone being natural.

There is no single correct answer; the best approach is to choose based on what you or your partner values most.

Points to Check Before Purchasing

① 4Cs (Carat, Color, Clarity, Cut)

Not all lab-grown diamonds are of uniform high quality. We recommend selecting your diamond after checking the 4Cs, just as you would with a natural diamond.

② Grading Reports and Quality Information

Some products are listed simply as “lab-grown diamond” without any 4C specifications. Checking for the presence of a grading report and the issuing institution (such as GIA or IGI) will make it easier to choose with confidence.

③ Purpose and Design

The design and setting you choose will vary depending on whether it is for an engagement ring, daily use, or an anniversary gift. We explain how to choose according to your needs in the related articles below.

④ Personal and Partner Values

Especially for jewelry you both will wear for a long time, such as an engagement ring, it is best to discuss your values regarding natural versus lab-grown beforehand.

For Those Who Want to Learn More

We have also prepared articles that explain each topic in more detail. Please take a look if any of these topics catch your interest.

• Will I regret buying a lab-grown diamond? 5 checklists to prevent regret
• Are lab-grown diamonds okay for engagement rings? Differences from natural ones and how to choose without regret
• Can lab-grown diamonds be worn daily? Durability, care, and tips for long-term use
• How to distinguish lab-grown diamonds: Differences from natural, moissanite, and cubic zirconia

Once you have a grasp of the basics, please take a look at our lab-grown diamond product list if you wish to see actual items.

Frequently Asked Questions

Q. Is a lab-grown diamond a fake?

A. No, it is not a fake. It is a real diamond composed of the same carbon crystals as a natural diamond. The FTC (U.S. Federal Trade Commission) states that both natural and lab-grown should be treated as “diamonds.”

Q. Can you distinguish it from a natural diamond by appearance?

A. Even for skilled appraisers, it is extremely difficult to distinguish them with the naked eye. They are identified through minute chemical analysis using specialized equipment.

Q. Is it the same as cubic zirconia or moissanite?

A. No, it is different. Cubic zirconia and moissanite are diamond substitutes (other minerals), whereas a lab-grown diamond is a real diamond made of the same carbon as a natural diamond.

Q. Is it okay to choose one for an engagement ring?

A. Yes, it is fine. However, whether it is suitable or not depends on your and your partner’s values.

Summary

Lab-grown diamonds are real diamonds identical to natural diamonds, yet they offer a different option when it comes to production, rarity, and compatibility with personal values.

Natural diamonds are suited for those who find value in them being “natural,” while lab-grown diamonds are for those who prioritize quality, rationality, and environmental or ethical considerations. There is no single correct answer; choosing based on what you value most will lead to a decision you won't regret.

If you have more specific questions, please refer to the related articles introduced in this post.