---
title: "What Is a Lab-Grown Diamond? How It's Made, Graded and Compared"
byline: "Love & Carat"
series: education
published: 2026-09-30T12:04:15.288Z
updated: 2026-09-30T12:04:15.288Z
canonical: https://loveandcaratnewyork.com/blog/what-is-a-lab-grown-diamond
disclosure: editorial
sources:
  - "HPHT and CVD Diamond Growth Processes | How Lab- ... - https://www.gia.edu/hpht-and-cvd-diamond-growth-processes"
  - "Laboratory-Grown Diamonds: An Update on Identification and Products Evaluated at GIA - https://www.gia.edu/gems-gemology/summer-2024-gia-update-on-laboratory-grown-diamonds"
  - "Simulants, Moissanite and Lab-Grown Diamonds | GIA 4Cs - https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/"
  - "Laboratory-Grown Diamond Report (LGDR) by GIA - https://discover.gia.edu/lgdr-by-gia"
  - "IGI - What is a Lab Grown Diamond (web) - https://www.igi.org/assets/pdf/retail-support/IGI_What%20are%20Laboratory%20Grown%20Diamond.pdf"
  - "More Info About Laboratory-Grown Diamonds | Gemological Institute of America - 4Cs - https://4cs.gia.edu/interactive-4cs/more-diamond-info/synthetics.html"
  - "Laboratory-Grown Diamond Services Details - https://www.gia.edu/gem-lab-service/laboratory-grown-diamond-grading-report-service"
---

# What Is a Lab-Grown Diamond? How It's Made, Graded and Compared

_Written by Love & Carat about the stones we sell. Not an independent review._

**The short answer**

- A lab-grown diamond is a diamond made by a technological process rather than a geological one, with essentially the same chemistry, crystal structure and optical properties as a mined diamond.
- It is grown in one of two ways: HPHT, which recreates high pressure and heat, or CVD, which builds diamond layer by layer from carbon-rich gas in a vacuum chamber.
- By eye it can be indistinguishable from a natural diamond, so check its GIA or IGI grading document or GIA quality assessment to confirm what you are buying.
- It usually costs less than a comparable natural diamond, but like any diamond it is not an investment.

A lab-grown diamond is a diamond made by people rather than by the earth. It has the same carbon crystal structure as a natural diamond, which formed over [millions to billions of years](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/) underground. It is not a fake and not a lookalike: GIA describes it as having [essentially the same chemical composition, crystal structure, optical, and physical properties](https://4cs.gia.edu/interactive-4cs/more-diamond-info/synthetics.html) as a diamond found in nature.

## What is a lab-grown diamond, exactly?

GIA's definition is that it is [man-made, the result of a technological process](https://4cs.gia.edu/interactive-4cs/more-diamond-info/synthetics.html), as opposed to the geological process that creates natural diamonds. The material itself is the same. Both are made of [tightly bonded carbon atoms](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/) in the same crystal structure, with nearly the same optical and physical properties.

> By eye, the difference can potentially be indistinguishable.
> (Simulants, Moissanite and Lab-Grown Diamonds | GIA 4Cs)

A simulant is a different thing. Stones made of glass, moissanite or cubic zirconia may look like diamond, but GIA notes they are [completely unrelated to diamonds at the atomic level](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/). A simulant can be a fine choice if you know what you're buying. It just isn't a diamond, and a lab-grown diamond is.

What separates lab-grown from natural is history, not substance. The two grow in very different environments, and that leaves tiny atomic-level irregularities called defects. GIA explains that the [species, distributions and relative concentrations](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/) of those defects reveal whether a diamond is natural or lab-grown. A gemological laboratory can read them. Those growth clues aren't something you can reliably read by eye.

## How are lab-grown diamonds made?

According to GIA, scientists first grew diamonds in a laboratory in the [mid-1950s](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes), though those were too small for jewelry. The first gem-quality ones followed in the [1970s](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/), and colorless lab-grown diamonds reached the jewelry market in commercial quantities in the mid-2010s. A [2016 account cited by GIA](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes) described industrial use as the material's primary function at that time.

There are two methods.

### HPHT: high pressure, high temperature

HPHT recreates some of the conditions deep in the earth where natural diamonds form. GIA describes a capsule holding a carbon source and a mixture of metals, heated to [1300-1600°C (2400-2900° F) under pressures of 5-6 GPa](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/). That is the equivalent of 150-190 km (about 90-120 miles) below the surface. The [molten metal dissolves the carbon](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes), and carbon atoms settle onto a small diamond seed crystal, which begins to grow.

How big the crystal gets depends on things like the growth time and the size of the capsule. In its [2024 update](https://www.gia.edu/gems-gemology/summer-2024-gia-update-on-laboratory-grown-diamonds), GIA recorded a 150.42 ct HPHT-grown crystal created in November 2021 as the largest lab-grown diamond documented at that time.

### CVD: chemical vapor deposition

CVD uses a different approach. It works at near-vacuum pressure instead of crushing force. GIA describes a vacuum chamber filled with [a hydrogen and carbon-containing gas, such as methane](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes). A source of energy such as a microwave beam breaks the gas down, and carbon settles onto flat diamond seed plates. Growth happens [layer by layer, like rain](https://www.igi.org/assets/pdf/retail-support/IGI_What%20are%20Laboratory%20Grown%20Diamond.pdf), as IGI puts it. GIA gives the chamber temperature as [about 900-1200°C](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes).

It isn't instant. GIA explains that the stones are taken out [every few days](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes) to polish off non-diamond carbon, then put back, and that the whole process can take three or four weeks. According to IGI, it takes [nearly one month](https://www.igi.org/assets/pdf/retail-support/IGI_What%20are%20Laboratory%20Grown%20Diamond.pdf) to grow a CVD crystal that can yield a 1.00 carat polished stone.

### Color treatment after growth

Some CVD lab-grown diamond crystals have a brownish color after growth. GIA explains that a brown color can be [removed by heat treatment](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes) before cutting. In [GIA's 2024 update](https://www.gia.edu/gems-gemology/summer-2024-gia-update-on-laboratory-grown-diamonds), about 80% of CVD lab-grown diamonds submitted to GIA had undergone post-growth HPHT treatment to improve their color grade.

We don't see that as a reason to avoid a stone. If treatment information matters to you, check whether the particular report or assessment includes it; GIA's report description says its Dossier omits that detail.

## Lab-grown, lab-created, synthetic: what's in a name?

You'll see several words for the same thing. GIA's technical writing has used "synthetic" for lab-grown diamonds; according to [GIA's 2024 update](https://www.gia.edu/gems-gemology/summer-2024-gia-update-on-laboratory-grown-diamonds), it began issuing reports on them in 2007. GIA's own history also mentions "lab-created" stones. You may also hear other names for a lab-grown diamond; we use "lab-grown" for clarity.

We say lab-grown, every time, for three reasons.

- **It's accurate.** The diamond grows as carbon accumulates on a seed crystal.
- **It's clear.** "Lab-grown" tells you both what it is (a diamond) and where it came from (a lab), with nothing hidden.
- **It avoids confusion.** "Synthetic" may suggest an imitation, but a lab-grown diamond is diamond.

For the fuller story on what the labels mean, including how the FTC approaches it, see our guide to whether [lab-grown diamonds are real diamonds](/blog/are-lab-grown-diamonds-real-diamonds).

## How is a lab-grown diamond cut and graded?

Once the rough crystal comes out of the press or chamber, it is [cut and polished by a diamond cutter](https://www.gia.edu/hpht-and-cvd-diamond-growth-processes), just as a mined rough would be. CVD crystals often have a rough black graphite edge that is cut away first.

GIA identifies lab-grown origin and provides a distinct [quality assessment](https://www.gia.edu/gem-lab-service/laboratory-grown-diamond-grading-report-service) for lab-grown diamonds. GIA's [description of its Laboratory-Grown Diamond Reports](https://discover.gia.edu/lgdr-by-gia) explains how those reports evaluated the 4Cs; its [current service page](https://www.gia.edu/gem-lab-service/laboratory-grown-diamond-grading-report-service) instead describes a distinct lab-grown diamond quality assessment. For any stone, check which grades its document actually supplies, including [cut](/education/cut), [color](/education/color), clarity and carat where listed. Here is what to look for on the report:

- **Identity.** GIA says its lab-grown diamond [quality assessment has a distinct format](https://www.gia.edu/gem-lab-service/laboratory-grown-diamond-grading-report-service) from natural-diamond reports. IGI's report likewise [authenticates the man-made nature](https://www.igi.org/assets/pdf/retail-support/IGI_What%20are%20Laboratory%20Grown%20Diamond.pdf) of the stone.
- **Growth method and treatment.** GIA's [description of its Laboratory-Grown Diamond Reports](https://discover.gia.edu/lgdr-by-gia) says the full version includes growth method and post-growth treatment, while the Dossier omits those details. GIA's [current service page](https://www.gia.edu/gem-lab-service/laboratory-grown-diamond-grading-report-service) describes quality assessments instead; check the actual document for the details it provides.
- **The inscription.** GIA says it laser-inscribes the girdle with ["Laboratory-Grown" and the quality assessment number](https://www.gia.edu/gem-lab-service/laboratory-grown-diamond-grading-report-service). Compare the inscription with the stone's document and use GIA's verification service.
- **Digital access.** GIA [describes its Laboratory-Grown Diamond Reports](https://discover.gia.edu/lgdr-by-gia) as digital; consult the document and GIA's verification service for the stone you're considering.

Every diamond we sell comes with a GIA or IGI grading report. Our glossary entry on [certificates](/education/certificate) walks through reading one line by line.

**Certified, always:** Choose a lab-grown diamond that comes with a GIA or IGI grading report. Because the eye can't tell lab-grown from natural, the report is your proof of what the stone is and how it grades.

## How does a lab-grown diamond compare with a mined one?

| | Lab-grown diamond | Natural diamond |
|---|---|---|
| Material | Crystalline carbon | Crystalline carbon |
| Formation | Technological growth process | Geological process over millions to billions of years |
| Telling them apart | Specialized testing | Specialized testing |
| Price | Usually less | Usually more |

In appearance and everyday wear, a lab-grown diamond and a comparable natural diamond can be remarkably alike. The difference may be invisible to the eye, but [specialized instruments and gemological laboratory testing](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/) can distinguish the two; GIA says its iD100 can do so [in under two seconds](https://4cs.gia.edu/en-us/simulants-moissanite-and-lab-grown-diamonds/).

The differences are in the story and the price. GIA puts it well: the two are gems with [vastly different creation processes and stories](https://discover.gia.edu/lgdr-by-gia), and people buy each with different things in mind. If an ancient stone from deep in the earth matters to you, that is a perfectly good reason to choose natural. If you want the look, the hardness and the fire for less money, lab-grown is the sensible pick.

One thing is the same for both. **Neither is an investment.** Buy a diamond because you love it, never on a promise of resale value.

GIA has reported a recent period of relatively little change in lab-grown diamonds. In [GIA's 2024 update](https://www.gia.edu/gems-gemology/summer-2024-gia-update-on-laboratory-grown-diamonds), it reported relatively few changes in lab-grown diamonds in the preceding five years. That suggests developments had largely stabilized, at least for then.

## So how should you spend on a lab-grown diamond?

Because lab-grown diamonds usually cost less than comparable natural ones, it's tempting to go straight for the top grades. Our advice is the opposite: spend where the eye can see it, and save where it can't.

- **Put the money into the cut.** Cut drives sparkle more than anything else on the report. A well-cut stone in a modest color grade may look better than a poorly cut stone with a top color grade.
- **Aim for eye-clean, not flawless.** Beyond the point where you can't see inclusions without magnification, higher clarity grades mostly add cost. Our guide to [eye-clean](/education/eye-clean) explains where that line sits.
- **Consider near-colorless, not necessarily colorless.** Compare stones in the setting you have in mind, especially yellow or rose gold; if you can't see a difference, choose the less expensive grade.
- **Choose a size you'll enjoy, not a number.** Compare well-cut stones on either side of a round carat weight; if they look the same to you, choose the less expensive one.

**Our rule of thumb:** When two stones look the same to you on the hand, buy the cheaper one. Spend what you save on the setting, or keep it.

If you're choosing a center stone now, these are good places to start. Browse more on our [center stones](/) page.

**A lab-grown diamond is a diamond: buy the cut, check the report, and don't pay for grades your eye can't see.**

## Frequently asked questions

**Is a lab-grown diamond a fake diamond?**

No. A lab-grown diamond is diamond: tightly bonded carbon in the same crystal structure as a mined stone. Simulants such as cubic zirconia, glass and moissanite are different materials; GIA tests diamonds it reports on to confirm their identity.

**Is it worth buying a lab-grown diamond?**

If you want the look of a diamond for less money, it is a sensible choice, because it usually costs less than a comparable natural stone. Buy it because you love it, not as an investment. No diamond is one, and nobody can promise you resale value.

**What are the downsides of lab-grown diamonds?**

You cannot reliably tell origin by eye, so check the GIA or IGI grading report accompanying the diamond. Post-growth treatment is common among CVD lab-grown diamonds submitted to GIA; if that detail matters to you, check whether the particular document includes it. Some buyers also prefer the story of a stone formed deep in the earth.

**How long does it take to grow a lab-grown diamond?**

GIA says the CVD growth process can take three or four weeks. According to IGI, it takes nearly one month to grow a CVD crystal that can yield a 1.00 carat polished stone.

**Can a jeweler tell the difference without a lab?**

Not by eye. GIA makes a desktop instrument, the GIA iD100, that helps jewelers separate natural diamonds from lab-grown diamonds and simulants in under two seconds, and full identification is done at a gemological laboratory.