Jewelry Glossary Guide

Lab-grown vs natural diamonds

A lab-grown diamond and a natural diamond are the same material: carbon crystallized as diamond, with essentially the same chemical, physical and optical properties. One formed deep in the earth over a very long time, and the other was grown in a factory. You cannot tell them apart by eye, so the grading report and the inscription on the stone are what tell you which one you are buying, and the difference shows up mostly in the price and the resale.

By Vadim Moda, Founder of Moda Clubs. Trading watches since 2017. Last updated

What each one is

Natural diamond
A natural diamond crystallized deep in the earth's mantle, where the pressure is high enough to hold carbon in its densest form. GIA's research puts most of them about 150 to 200 kilometers down, and some are more than three billion years old. Volcanic eruptions later carried them toward the surface in the rock known as kimberlite, which is where they are mined.
Lab-grown diamond
A lab-grown diamond is grown in a factory by one of two methods. HPHT (high pressure, high temperature) recreates conditions like those inside the earth, turning a carbon source into diamond around a small diamond seed. CVD (chemical vapor deposition) feeds a carbon-bearing gas, usually methane, into a reactor, where the carbon settles onto diamond seeds layer by layer. Either way the result is diamond, not an imitation. Some stones are also treated after growth to change their color.
What the law calls them
In 2018 the US Federal Trade Commission concluded that lab-grown stones have essentially the same optical, physical and chemical properties as mined diamonds, so they are diamonds. A seller still has to disclose clearly that a stone is not mined, with a word like laboratory-grown, laboratory-created or the maker's name followed by created. Moissanite and cubic zirconia are simulants: different materials that only resemble diamond.

How each one is graded

A natural diamond is graded on the 4Cs: color, clarity, cut and carat weight. A GIA or IGI report for a natural stone carries those grades on the familiar scales.

Reports for lab-grown stones are deliberately different. GIA's lab-grown reports have their own look, state the growth method, CVD or HPHT, and say whether the stone may have been treated after growth. Since October 1, 2025, GIA no longer grades a lab-grown diamond's color and clarity on the scale it uses for natural stones; it confirms the stone is laboratory-grown and describes its quality as Premium or Standard, because most lab-grown diamonds fall in a narrow range of color and clarity.

IGI's lab-grown reports likewise name the growth process, CVD or HPHT, and state whether the stone shows any indication of treatment after growth. Whichever lab graded it, a report for a lab-grown stone says so on its face.

How to tell them apart

Not by eye, and not with a loupe. GIA says ordinary gemological observation and standard instruments cannot separate a lab-grown diamond from a natural one. Gem labs screen every stone with specialized equipment: infrared spectroscopy to sort stones for further testing, photoluminescence spectroscopy, and imaging of the growth structure under ultraviolet light, which looks different in a natural diamond and a grown one.

  • Read the report. A GIA or IGI report for a lab-grown diamond states that it is lab-grown and names the growth method. A natural diamond's report carries no such statement.
  • Match the inscription. GIA laser-inscribes the girdle of a lab-grown diamond it grades with the report number and the words laboratory-grown, and IGI's inscriptions on lab-grown stones carry a lab-grown marking with the report number. The number on the stone should match the number on the report.
  • No report, no answer. For a stone with no report, GIA's advice is to send it to a gem lab for testing before you rely on what you were told.

Price and resale

A lab-grown diamond costs much less than a natural diamond of the same size and quality, which is why buyers pick it when they want a larger or finer stone for the money. Lab-grown prices have also kept falling for several years as production has grown, according to wholesale price tracking in the trade press.

That shapes resale. Lab-grown diamonds can be made in any quantity, so a lab-grown stone resells for little compared with what it cost, and it is best bought to wear rather than as something to sell later. Natural diamonds cost more because they are rarer and formed in nature, and they tend to hold a stronger resale market. Neither guarantees a price later, and this guide does not quote one.

What Moda Diamonds offers

Moda Diamonds is the jewelry side of Moda Clubs, run by David Moda in Sioux Falls, South Dakota. David sources both lab-grown and natural diamonds and designs custom engagement rings and fine jewelry in CAD, so you see the piece before it is made. Every diamond Moda sells is certified, and you see the certificate before you buy. David works with both GIA and IGI and prefers GIA when possible, the choice is yours, and Moda does not deal in ungraded stones.

Selling a stone instead? Tell David its specs and whether it is natural or lab-grown, and diamond prices are quoted per item. Moda can also appraise a ring bought elsewhere. Text David at (605) 941-0930.

Sources

The general facts on this page come from GIA and the jewelry trade press, read on 2026-10-26. What Moda Diamonds offers comes from the Moda Diamonds page.

Common questions

Is a lab-grown diamond a real diamond?
Yes. It is carbon crystallized as diamond, with essentially the same chemical, physical and optical properties as a mined diamond, and the US Federal Trade Commission treats it as a diamond. A seller has to say clearly that it is lab-grown, with a word such as laboratory-grown or laboratory-created. Moissanite and cubic zirconia are different materials that only look like diamond.
Can a jeweler tell lab-grown from natural with a loupe?
No. GIA says ordinary gemological observation and standard instruments cannot separate the two. Gem labs use specialized screening, such as infrared and photoluminescence spectroscopy and imaging of the stone's growth structure. For a loose or set stone, the practical check is the grading report and the matching laser inscription on the girdle.
How does GIA grade a lab-grown diamond?
Since October 1, 2025, GIA no longer gives lab-grown diamonds color and clarity grades on the scale it uses for natural diamonds. Its lab-grown reports confirm the stone is laboratory-grown, state the growth method, CVD or HPHT, and describe its quality as Premium or Standard. GIA said the change reflects how most lab-grown diamonds fall in a narrow range of color and clarity.
Do lab-grown diamonds hold their value?
Not the way natural diamonds tend to. Lab-grown diamonds can be made in any quantity, and their wholesale prices have kept falling as production has grown, so resale offers on a lab-grown stone are low compared with what it cost. Natural diamonds cost more because they are rarer and formed in nature, and they tend to hold a stronger resale market.
Does Moda Diamonds sell lab-grown or natural?
Both. David Moda sources lab-grown and natural diamonds. Every diamond Moda sells is certified and you see the certificate before you buy. David works with both GIA and IGI and prefers GIA when possible, the choice is yours, and Moda does not deal in ungraded stones.

Related glossary terms

About the author

Vadim Moda

Founder of Moda Clubs

Has been trading luxury watches since 2017, before founding Moda Clubs in 2018. Moda Clubs operates 23 buy/sell communities across watches, cars, diamonds, and other luxury goods, with 600,000+ members, run out of Moda HQ in Sioux Falls, SD.

← Back to all watch dealer slang terms