Natural Diamonds vs. Lab Grown Diamonds: What to Know

A lab-grown diamond and a natural diamond are both equally true diamonds. They share the same chemical composition, crystal structure, and hardness, and they sparkle the same way on your hand. What separates them is where they came from, how rare they are, what they cost, and whether they qualify for our trade-up guarantee. We sell both, and our jewelry consultants explain the trade-offs instead of steering you to one side.

For more details how lab-grown diamonds are grown, graded, and certified, read our guide to what lab-grown diamonds are and why they work for engagement and wedding rings. For details on what sets a natural diamond apart and the settings to build on, read our post on the timelessness and uniqueness of natural diamonds.

Key Takeaways

• Lab-grown and natural diamonds have the same chemistry and hardness, and GIA grades both on the same 4Cs scale.
• More than half of engagement ring center stones sold today are lab-grown, because the same budget buys a larger or higher-grade stone.
• When choosing diamonds, we hold both types to the same standard, and both carry our Lifetime Diamond, Sapphire, and Ruby Limited Warranty. Additionally, natural diamonds qualify for our 110% Natural Diamond Trade-Up Guarantee.

What Is the Difference Between Lab-Grown and Natural Diamonds?

The Federal Trade Commission defines a diamond as pure carbon crystallized in the isometric system, and it allows the word “diamond” for a laboratory-grown stone as long as the origin is clearly disclosed (16 CFR 23.12). GIA states that lab-grown diamonds have essentially the same chemical composition, crystal structure, and physical properties as natural diamonds, and that they are just as hard (GIA).

High pressure and high temperature (HPHT) equipment mimics the conditions inside the earth. Chemical vapor deposition (CVD) breaks down a carbon-containing gas in a vacuum chamber so carbon crystallizes onto a diamond seed plate. Either way the crystal is finished in days or weeks, then cut and polished by a diamond cutter (GIA Research).

You cannot tell them apart by eye, and neither can we at the counter. GIA reports that only a gemological lab with advanced testing equipment can authoritatively separate them. GIA grades both by the same 4Cs standards, issues a separate Laboratory-Grown Diamond Report, and laser-inscribes “laboratory-grown” on the lab-grown stone’s girdle. Our guide to the 4Cs of diamonds explains those grades.

Lab-Grown vs. Natural Diamond Price and Value

Sixty-one percent of engagement ring center stones are lab-grown, according to The Knot’s 2026 Real Weddings study, and The Knot’s editorial director, Esther Lee, named economic pragmatism as the number one reason (National Jeweler). A lab-grown diamond often costs less than a natural diamond of the same size and grade, so the same budget buys a larger stone, a higher color, or a cleaner clarity.

Supply of natural diamonds is limited. Our natural diamonds include a 110% Natural Diamond Trade-Up Guarantee: on a qualifying ring, solitaire earrings, or solitaire pendant of 1/4 carat or more, we credit 110 percent of your original purchase price, any time from six months after purchase, toward a new diamond piece priced at least twice as much. The full terms are on our product protection page.

We curate both kinds the same way. Only 1 in 10 of the world’s most beautiful & radiant diamonds makes the cut. Every RB Select natural diamond is chosen by our diamond curator beyond its certificate and sourced in accordance with the Kimberley Process. Our certified lab-grown diamonds come from respected growers, and we have carried them for over a decade. Compare both types in our loose diamond search before you commit to a setting.

Natural Diamond Engagement Rings

These complete rings from our Poem collection each hold a natural center diamond, a round, an oval, and a pear, in 14k white and yellow gold. Browse the full range of natural diamond engagement rings.

Poem 14k White Gold Natural Diamond Engagement Ring 1 ct. tw.

• Complete ring with a natural round center diamond
• 14k white gold
• 1 ct. tw. of natural diamonds

Poem 14k Yellow Gold Natural Diamond Engagement Ring 1 ct. tw.

• Complete ring with a natural oval center diamond
• 14k yellow gold
• 1 ct. tw. of natural diamonds

Poem 14k White Gold Natural Diamond Engagement Ring 1 1/3 ct. tw.

• Complete ring with a natural pear center diamond
• 14k white gold
• 1 1/3 ct. tw. of natural diamonds

Lab-Grown Diamond Engagement Rings

Eternalle is our exclusive lab-grown collection, sold as complete rings with certified center stones. These picks span platinum and 14k yellow and white gold with a princess cut, a radiant, and a marquise center. See everything in lab-grown diamond engagement rings.

Eternalle Platinum Lab-Grown Diamond Engagement Ring 2 ct. tw.

• Complete ring with a lab-grown princess cut center
• Platinum
• 2 ct. tw. of lab-grown diamonds

Eternalle 14k Yellow Gold Lab-Grown Diamond Engagement Ring 2 ct. tw.

• Complete ring with a lab-grown radiant center
• 14k yellow gold
• 2 ct. tw. of lab-grown diamonds

Eternalle 14k White Gold Lab-Grown Diamond Engagement Ring 4 ct. tw.

• Complete ring with a lab-grown marquise center
• 14k white gold
• 4 ct. tw. of lab-grown diamonds

How to Choose Between a Lab-Grown and a Natural Diamond

Choose by origin, budget, and what you want the stone to do for you later. Work through it in four steps.

• Decide what origin means to you. If a stone that formed in the earth millions to billions of years ago is important to you, choose natural. If the finished look and the grade are the point, either type delivers.
• Price both at the carat weight you want. The gap between the natural and the lab-grown stone tells you which one fits the budget you set.
• Think past the proposal. Choose lab-grown as the stone you will keep. Choose natural if you may want to trade up to a larger diamond later.
• See both loose, side by side. Book a Diamond Discovery Experience at one of our showrooms and handle natural and lab-grown diamonds under the same light with our jewelry consultants.

As we recently noted in an interview with Inquisitor: “Some prioritize origin, rarity, or long-term value. Others appreciate the size and affordability that lab-grown diamonds offer. Our role is to educate, support, and help each couple choose the diamond that aligns with their vision and feels right for them.”

The Robbins Brothers Difference

Our master jeweler is in-house for sizing and future resets, our VIP diamond viewing rooms let you compare loose stones under ideal lighting, and our jewelry consultants guide rather than pressure.

Frequently Asked Questions

Are lab-grown diamonds real diamonds?

Yes. A lab-grown diamond is pure carbon in the same crystal structure as a natural diamond, which is the FTC’s definition of a diamond. Cubic zirconia and moissanite are the ones to watch for: GIA notes they only look like diamond and have very different chemical and physical properties.

Are lab-grown diamonds as good as natural diamonds?

In hardness and sparkle, yes. GIA grades a lab-grown diamond on the same cut, color, clarity, and carat scale as a natural diamond, and our lab-grown diamonds are certified by SGS for sustainable production and curated to the same standard as our RB Select natural diamonds.

What are the downsides of lab-grown diamonds?

A lab-grown diamond is not rare, so it is excluded from our 110% Natural Diamond Trade-Up Guarantee, and it has no geological origin story, which some couples want in an heirloom.

Can a jeweler tell the difference between a natural and a lab-grown diamond?

Not by eye. Ask for the report and the girdle inscription: GIA issues a separate Laboratory-Grown Diamond Report and inscribes “laboratory-grown” on the stone, and our jewelry consultants show you both at the counter.

What do jewelers think of lab-grown diamonds?

We sell both without judgment. Our lab-grown diamonds come from respected growers, are certified by SGS for sustainable production, and pass the same selection criteria as our natural diamonds.

Do you offer both lab-grown and natural diamonds for engagement rings?

Yes. Shop complete natural diamond engagement rings and lab-grown diamond engagement rings, or start with a loose stone of either type in our loose diamond search.

Or find a Robbins Brothers near you to see natural and lab-grown diamonds side by side.