Natural Diamonds vs Lab-Grown Diamonds vs Diamond Simulants: What's the Difference?

Natural diamonds, lab-grown diamonds, synthetic diamonds, simulated diamonds, CZ and moissanite—the terminology can be confusing when you first start shopping for jewelry.

The most important distinction is:

A laboratory-grown diamond is a diamond. A diamond simulant is not a diamond.

Natural and laboratory-grown diamonds share essentially the same crystal structure and chemical, physical and optical properties, with their main difference being how and where they are formed.

Diamond simulants, on the other hand, are different materials designed to imitate the appearance of diamond. Common examples include cubic zirconia (CZ) and synthetic moissanite.

A simple way to remember the difference is:

Natural Diamond = a diamond formed naturally

Laboratory-Grown Diamond = a diamond grown in a laboratory

Diamond Simulant = a different material designed to look like diamond

What Is a Natural Diamond?

A natural diamond forms through geological processes deep within the Earth.

It consists essentially of carbon arranged in the crystal structure characteristic of diamond.

After being mined, rough diamonds may be cut and polished for use in jewelry.

Natural diamonds can be evaluated using factors including Carat, Color, Clarity and Cut—the well-known 4Cs.

However, the term “natural diamond” describes its origin, not simply its appearance.

A colorless, sparkling stone is not automatically a natural diamond.

What Is a Lab-Grown Diamond?

A laboratory-grown diamond is a diamond produced in a controlled laboratory or industrial environment.

Two of the main growth methods are:

HPHT — High Pressure High Temperature

and

CVD — Chemical Vapor Deposition.

Although their growth environment is different from that of natural diamonds, GIA states that laboratory-grown diamonds have essentially the same chemical composition, crystal structure, optical and physical properties as diamonds formed in nature.

For this reason, simply calling a lab-grown diamond a “fake diamond” is inaccurate.

Are Lab-Grown Diamonds Real Diamonds?

Yes.

In gemological terms, a Laboratory-Grown Diamond is diamond.

It is not cubic zirconia, moissanite or another diamond imitation.

The U.S. Federal Trade Commission also treats laboratory-grown diamonds and diamond simulants as different categories. Laboratory-grown diamonds should be clearly disclosed as laboratory-grown or laboratory-created, while imitation stones should be identified as simulated or imitation so consumers understand what they are buying.

Therefore:

Lab-Grown Diamond ≠ Diamond Simulant.

What Is the Difference Between a Natural and Lab-Grown Diamond?

The biggest difference is origin and growth process.

Natural diamonds form through natural geological processes inside the Earth. Laboratory-grown diamonds are produced through technologies such as HPHT and CVD under controlled conditions.

Once cut and polished, however, it is generally not possible to reliably determine origin simply by looking at a diamond.

Because natural and laboratory-grown diamonds are so similar chemically and optically, GIA explains that advanced testing—including spectroscopy, fluorescence patterns, growth characteristics and other diagnostic features—may be required for reliable identification.

So:

Not being able to see a difference with the naked eye does not mean there are no detectable differences.

It means origin identification generally requires appropriate testing.

Do All Lab-Grown Diamonds Contain No Nitrogen?

This is too broad a statement.

Older explanations sometimes simplify diamond identification by saying that natural diamonds contain nitrogen while laboratory-grown diamonds do not.

In reality, diamond type, growth method, color, impurities and post-growth treatment make identification more complex.

GIA research shows that many colorless to near-colorless laboratory-grown diamonds are Type II, with no nitrogen detectable by the relevant spectroscopy, but laboratory-grown diamonds can display different trace elements, inclusions and growth characteristics depending on how they were produced.

Nitrogen alone should therefore not be used by consumers as a simple home test for diamond origin.

Do Lab-Grown Diamonds Come With GIA Certificates?

A more accurate answer is:

A laboratory-grown diamond can be submitted to a qualified gemological laboratory for identification or quality assessment, but not every lab-grown diamond automatically comes with a GIA document.

GIA's services for laboratory-grown diamonds have also changed.

Since October 1, 2025, qualifying colorless to near-colorless laboratory-grown diamonds submitted to GIA are evaluated through the Laboratory-Grown Diamond Quality Assessment, which uses overall Premium or Standard classifications rather than simply applying the full natural-diamond grading nomenclature. Qualifying stones are also laser-inscribed with “Laboratory-Grown” and their assessment number.

This is why older articles describing GIA's 2019 laboratory-grown diamond reporting system may now be outdated.

What Is a Diamond Simulant?

A Diamond Simulant is a material that looks similar to diamond but is not itself diamond.

Simulants can be colorless, transparent and highly reflective, making them attractive for jewelry designed to achieve a diamond-like appearance.

Common diamond simulants include:

Cubic Zirconia (CZ)

Synthetic Moissanite

and a range of other natural or manufactured materials.

GIA explains that simulants have different atomic structures and different chemical and physical properties from both natural and laboratory-grown diamonds.

What Is the Main Difference Between a Diamond Simulant and a Lab-Grown Diamond?

The simplest answer is:

A lab-grown diamond is Diamond.

A diamond simulant is not Diamond.

Laboratory-grown diamond has the crystal structure and fundamental properties of diamond.

A simulant uses another material to produce a similar visual effect.

That is why the two categories can differ significantly in hardness, density, optical behavior, price and product positioning even when both appear bright and sparkling.

Is Cubic Zirconia a Lab-Grown Diamond?

No.

Cubic Zirconia, commonly abbreviated as CZ, is a widely used Diamond Simulant.

CZ is manufactured in a laboratory, but being “lab-created” does not make a material a Laboratory-Grown Diamond.

GIA lists CZ at approximately 8.5 on the Mohs hardness scale, compared with diamond at 10. Its chemistry, crystal structure and physical properties are different from diamond.

Therefore:

Lab-Created CZ ≠ Lab-Grown Diamond.

“Lab-created” tells you where something was manufactured.

The material itself tells you what it actually is.

Is Moissanite a Lab-Grown Diamond?

No.

Synthetic moissanite is another commonly used Diamond Simulant.

It can be highly brilliant and relatively hard, but its chemical composition and crystal structure differ from diamond.

CZ, synthetic moissanite and laboratory-grown diamonds may all be produced by people, but they are three different materials.

Does “Diamond Simulant” Mean Fake Jewelry?

Not when the material is clearly disclosed.

Diamond Simulants are a legitimate category of jewelry material when consumers are accurately told what they are purchasing.

The FTC's jewelry guidance specifically emphasizes clear disclosure: simulated or imitation stones should be identified in a way that makes it clear they are not mined or laboratory-grown diamonds.

For us, the important point is transparency.

Different materials can suit different budgets, styles and purposes.

What matters is knowing exactly what the jewelry contains before you buy it.

Natural Diamond vs Lab-Grown Diamond vs Diamond Simulant

Professional testing is generally required to distinguish natural from laboratory-grown diamond reliably, while simulants tend to be more readily separated because their physical and optical properties differ from diamond.

Does MONI Use Natural Diamonds, Lab-Grown Diamonds or Diamond Simulants?

Different MONI collections use different stones, so there is no single answer that applies to every piece we make.

Many of our 925 sterling silver rings, necklaces, earrings and bracelets feature MONI Diamond Simulants, often paired with 18K Gold Vermeil over 925 sterling silver.

These are positioned as Diamond Simulants. They are not natural diamonds and should not be confused with Laboratory-Grown Diamonds.

Some of our solid-gold collections, however, use Natural Diamonds. Selected 18K and 9K Solid Gold product pages explicitly list Natural Diamond as part of their material specifications.

The easiest way to know what you are choosing is to check the Material information on each product page:

MONI Diamond Simulants = our diamond simulant stones

Natural Diamond = naturally formed diamond

Product specifications should always be checked individually.

Which Should You Choose: Natural, Lab-Grown or a Diamond Simulant?

There is no single right choice for everyone.

If natural origin and the characteristics of a naturally formed diamond are important to you, a Natural Diamond may suit your priorities.

If you want a piece made with actual diamond material but are comfortable with a laboratory origin, a Laboratory-Grown Diamond may be worth exploring.

If your priorities are jewelry design, sparkle, everyday styling and a more accessible price point, a Diamond Simulant can be another option.

The most useful question is not:

“Which one is real?”

It is:

“Do I clearly understand what material this piece of jewelry uses?”

Clear material information makes better jewelry decisions possible.

Diamond & Diamond Simulant FAQs

Are lab-grown diamonds fake diamonds?

No. Laboratory-grown diamonds have essentially the same chemical composition, crystal structure and physical and optical properties as natural diamonds. Their key difference is origin.

Are lab-grown diamonds and diamond simulants the same?

No. A laboratory-grown diamond is diamond. A Diamond Simulant uses another material to imitate the visual appearance of diamond.

Is CZ a diamond?

No. Cubic Zirconia is a common Diamond Simulant with different chemical, physical and crystal properties from diamond.

Is moissanite a diamond?

No. Synthetic moissanite is a common Diamond Simulant, not a natural or Laboratory-Grown Diamond.

Can you tell a natural diamond from a lab-grown diamond by eye?

Usually not reliably. Their fundamental properties and appearance can be extremely similar, so professional gemological testing is generally required to confirm origin.

Does every lab-grown diamond have a GIA certificate?

No. A stone has to be submitted to an appropriate laboratory service and meet relevant requirements. GIA currently offers a Laboratory-Grown Diamond Quality Assessment for qualifying stones.

Does every MONI piece use Diamond Simulants?

No. Many of our 925 sterling silver pieces use MONI Diamond Simulants, while selected 9K, 14K and 18K Solid Gold pieces feature Natural Diamonds. Always check the individual product page.

Are MONI Diamond Simulants lab-grown diamonds?

No. Our product pages identify them as MONI Diamond Simulants, which is a different category from Laboratory-Grown Diamond.

Don't Just Ask “Is It a Real Diamond?”—Ask What It Actually Is

Jewelry terminology can be confusing because words such as “man-made,” “lab-created” and “grown” sound similar even when they describe completely different materials.

The simplest distinction is:

Natural and laboratory-grown diamonds are both diamonds with different origins. A Diamond Simulant is a different material designed to create a diamond-like appearance.

At MONI, different collections use different stones. Many of our sterling silver designs feature MONI Diamond Simulants, while selected solid-gold pieces use Natural Diamonds.

You do not need to guess from appearance.

Check the Material section on the individual product page to know exactly what you are choosing.

References: Gemological Institute of America (GIA); U.S. Federal Trade Commission (FTC)

This article provides general information about diamonds and jewelry materials. Natural diamonds, laboratory-grown diamonds and different Diamond Simulants can have different product specifications. For MONI jewelry, always refer to the latest individual product page for the exact stone and metal materials.