A decade ago, most jewelers barely stocked lab grown diamond engagement rings. Today, they sit next to mined stones in nearly every showcase, and a large share of couples pick them on purpose, not as a fallback. The reason is simple math: a lab grown diamond is chemically and optically identical to a mined one, yet it typically costs far less for the same size and quality. That price gap lets couples put a bigger stone on the hand, save for the wedding, or both. This guide walks through what lab grown diamonds actually are, how they’re graded, what fair pricing looks like, and how to shop for one without getting talked into something you didn’t ask for. Whether you already know you want a lab grown center stone or you’re still comparing it against a mined one, you’ll leave with a clear plan.
What Is a Lab Grown Diamond, Exactly?
A lab grown diamond is pure crystallized carbon grown inside a laboratory instead of forming underground over billions of years. The Federal Trade Commission defines a diamond, mined or lab grown, as a mineral made of essentially pure carbon crystallized in the isometric cubic system. A lab grown stone meets that definition. It has the same hardness, the same brilliance, and the same chemical makeup as a mined diamond. The only real difference is where it came from and how long it took to form.
How Lab Grown Diamonds Are Made
Manufacturers use one of two processes to grow a diamond from a tiny carbon seed.
The HPHT Method
HPHT stands for high pressure, high temperature. A seed crystal is placed in carbon under extreme pressure and heat that mimic the conditions deep in the earth, and the carbon bonds to the seed layer by layer. This was the first method used to create gem quality diamonds and is still common today.
The CVD Method
CVD stands for chemical vapor deposition. A seed is placed in a sealed chamber filled with carbon rich gas. The gas is heated until carbon atoms break free and settle onto the seed, building the crystal from the bottom up. CVD uses less energy than HPHT and has become the more common method for jewelry grade stones in recent years.
Lab Grown vs Mined Diamonds: What Actually Differs
Set side by side, a well cut lab grown diamond and a mined diamond of the same grade look identical to the naked eye, and even to most jewelers without lab equipment. Here’s how they actually compare.
| Factor | Lab Grown Diamond | Mined Diamond |
|---|---|---|
| Chemical makeup | Pure carbon, cubic crystal structure | Pure carbon, cubic crystal structure |
| Hardness | 10 on the Mohs scale | 10 on the Mohs scale |
| Formation time | Weeks to months | One to three billion years |
| Grading | Graded by GIA and IGI with lab grown specific reports | Graded by GIA and IGI with standard reports |
| Typical price for the same specs | Meaningfully lower per carat | Higher per carat |
| Resale value | Currently low resale as a percentage of retail | Also low resale, but a more established secondary market |
Are Lab Grown Diamonds Real Diamonds?
Yes. This isn’t a marketing claim, it’s the official position of the FTC and the diamond grading industry. The Gemological Institute of America has graded laboratory grown diamonds since 2007 and treats them as genuine diamonds with a distinct origin, not as imitations. Simulants like cubic zirconia and moissanite are different materials that only resemble diamonds. A lab grown diamond is not a simulant. It’s a diamond that started in a machine instead of the mantle.
Where the two do differ, by law, is disclosure. Under the FTC’s Jewelry Guides, a seller must clearly state that a diamond is lab grown, and cannot describe it in a way that lets a shopper reasonably assume it’s mined. If a listing just says diamond ring with no origin mentioned anywhere, ask directly before you buy.
How Much Do Lab Grown Diamond Engagement Rings Cost?
Pricing varies by retailer, but the pattern is consistent: a lab grown diamond typically costs meaningfully less than a mined diamond of the same carat weight, color, clarity, and cut. That gap tends to widen as carat size goes up, since large, high clarity mined diamonds are rare and priced accordingly, while large lab grown stones are easier to produce at scale.
Why Lab Grown Diamonds Cost Less
- Production scale. Growing a diamond in a controlled facility is faster and more predictable than mining, and supply has expanded quickly since 2020.
- No exploration or mining costs. There’s no drilling, land rights, or ore processing involved.
- Less rarity premium. Mined diamonds, especially larger or flawless ones, carry a scarcity value that lab grown stones don’t.
- Competitive pricing among growers. More companies growing diamonds means more competition on price.
How to Choose a Lab Grown Diamond for Your Ring
The 4Cs Still Matter
Cut, color, clarity, and carat weight determine how a diamond looks and what it’s worth, whether it’s mined or lab grown.
- Cut: affects sparkle more than any other factor. A well cut diamond looks brighter even at a lower color or clarity grade.
- Color: graded from D (colorless) to Z (light yellow or brown). Most engagement ring buyers land comfortably in the near colorless range, G through I.
- Clarity: measures internal and surface characteristics. Lab grown diamonds often present very few inclusions, but grades still range from flawless down to included.
- Carat: is simply weight, not size. Two diamonds of the same carat weight can look different in diameter depending on how they’re cut.
Check the Certification: GIA vs IGI
Always buy a lab grown diamond with an independent grading report, not just a store appraisal. GIA and IGI are the two most recognized labs for lab grown stones.
As of October 2025, GIA changed how it evaluates most lab grown diamonds in the D to Z color range. Instead of assigning the same detailed color and clarity nomenclature used for natural diamonds, GIA now issues a Laboratory-Grown Diamond Quality Assessment that rates the stone as Premium or Standard, based on an overall review of its color, clarity, and cut. GIA made this change because it wants natural diamond terminology reserved for natural diamonds, even though lab grown stones are chemically identical. IGI, by contrast, still issues full 4Cs style reports for lab grown diamonds, which is part of why IGI reports are common in the lab grown market. Neither approach makes a diamond better or worse. It just changes how the paperwork reads, so ask your jeweler which lab issued the report and what the grading terms mean before you compare two rings side by side.
Best Diamond Shapes for Lab Grown Engagement Rings
Shape is a personal choice, but a few consistently perform well in lab grown stones because of how CVD and HPHT crystals grow and get cut.
- Round brilliant: the most popular shape overall, prized for maximum sparkle.
- Oval: elongates the finger and tends to look larger per carat than a round stone.
- Cushion: a soft, rounded square that hides small inclusions well.
- Emerald: a step cut that shows off clarity, so buy the highest clarity grade your budget allows.
- Radiant: combines brilliance with a more geometric outline.
Setting Styles That Pair Well With Lab Grown Diamonds
Because lab grown diamonds free up budget, many couples put the savings into the setting.
- Solitaire: a single stone on a plain band, letting the diamond do all the talking.
- Halo: a ring of smaller diamonds around the center stone that increases apparent size.
- Three stone: a center diamond flanked by two side stones, often chosen for its symbolism.
- Pave or vintage detail: small diamonds set into the band itself for extra sparkle without a large center stone.
Do Lab Grown Diamond Rings Hold Their Value?
Be honest with yourself here: no diamond, lab grown or mined, is a reliable investment. Diamonds of both kinds typically resell for a fraction of their retail price, because retail pricing includes cutting, grading, marketing, and retailer margin that a resale buyer won’t pay for. Lab grown diamonds currently resell for less, as a percentage of original price, than mined diamonds, largely because supply keeps growing and older stones compete with newer, cheaper production. If resale value matters to you, buy the ring because you or your partner will wear and love it, not as a store of value, and keep the original grading report and receipt, since documentation matters more than origin when it’s time to sell or insure.
Common Myths About Lab Grown Diamonds
| Myth | Fact |
|---|---|
| They’re fake diamonds. | They are chemically, physically, and optically real diamonds. Only the origin differs. |
| They’ll turn yellow or cloudy over time. | Diamond is one of the most chemically stable materials that exists. Normal wear does not change its color or clarity. |
| Jewelers can’t tell them apart from mined diamonds by eye. | That’s true, which is exactly why an independent grading report matters. |
| A lab grown diamond ring has no resale value at all. | It has some resale value, just a smaller percentage of retail than most buyers expect, similar to mined diamonds. |
Step by Step: How to Buy a Lab Grown Diamond Engagement Ring
- Set a total budget first, including the setting, before you fall in love with a specific stone.
- Decide on a shape and rough carat range together, if it’s a joint decision.
- Prioritize cut quality above color and clarity for the best visible sparkle.
- Ask for the independent grading report, GIA or IGI, and confirm the growth method listed on it.
- Compare the total price against a mined diamond of the same specs so you know exactly what you’re saving.
- Get the ring appraised and insured once it’s purchased, using the grading report as documentation.
Quick tip: Ask to see the diamond outside the store’s lighting. Jewelry store lighting is designed to maximize sparkle, and a diamond that looks incredible under it should still look great in daylight or under a phone flashlight.
Red Flags to Watch For
- A listing that never states whether the diamond is lab grown or mined anywhere in the description.
- No independent grading report offered, only an in house appraisal.
- Pressure to decide the same day with a discount that expires in hours.
- A price that seems far below the market range for the stated carat, color, and clarity, which can signal a much lower actual grade.
Conclusion
A lab grown diamond engagement ring gives you a genuine diamond, backed by the same grading standards as a mined stone, at a price that lets you choose a bigger center stone, a nicer setting, or simply spend less without cutting a single corner on quality. The key is buying from a jeweler who discloses the origin clearly and provides an independent grading report. Compare a few options, ask the questions above, and choose the ring that fits both your budget and the person who’s going to wear it every day.
Frequently Asked Questions
Are lab grown diamonds cheaper than mined diamonds of the same quality?
Yes. For the same carat weight, cut, color, and clarity, a lab grown diamond typically costs meaningfully less than a mined one, and the gap tends to grow with carat size.
Will a lab grown diamond show up differently under a jeweler’s loupe?
Not to the naked eye. Telling a lab grown diamond apart from a mined one usually requires specialized lab equipment that detects trace growth patterns, which is why a grading report matters more than a visual inspection.
Does GIA still grade lab grown diamonds with the 4Cs?
For most D to Z lab grown diamonds, GIA now uses a simplified Premium or Standard quality assessment instead of full natural diamond nomenclature, a change GIA introduced in October 2025. IGI continues to issue full 4Cs style reports for lab grown stones.
Is it okay to propose with a lab grown diamond?
Completely. There is no rule, tradition, or requirement that an engagement ring use a mined stone. What matters is that the ring fits the person and the relationship, not where the carbon came from.
Do lab grown diamonds require special care or cleaning?
No. They’re cleaned and cared for exactly like mined diamonds, warm water, mild soap, a soft brush, and a periodic professional check of the setting.
Can a lab grown diamond be insured?
Yes. Most jewelry insurers cover lab grown diamonds the same way they cover mined ones, as long as you provide the grading report and a receipt or appraisal.
What’s the difference between a lab grown diamond and moissanite or cubic zirconia?
Moissanite and cubic zirconia are different minerals that only look like diamonds. A lab grown diamond is chemically identical to a mined diamond. It is not a substitute or simulant, it’s a diamond by definition.
Sources
FTC: In the Loupe, Advertising Diamonds, Gemstones and Pearls
GIA: Updated Laboratory-Grown Diamond Services, October 2025
