# Lab-Grown Diamonds: What They Are, How They Are Made, Certificate and Price

- Link: https://www.simattabijoux.com/en/lab-grown-diamond/
- Published: 2026-10-27T05:38:56+01:00
- Author: Simatta Bijoux

**In short** A lab-grown diamond, also called a lab diamond, lab-created diamond
or synthetic diamond, is a **real diamond**: pure carbon, with the same hardness(
10 on the Mohs scale), the same sparkle and the same composition as a natural diamond.
The only difference is its origin: it is created in a laboratory in a few weeks,
under high pressure (HPHT) or by carbon deposition (CVD), instead of forming in 
the Earth over millions of years. With the naked eye, and even under a loupe, nothing
sets them apart; only a properly equipped laboratory can tell the difference. For
the same quality, it costs far less than a natural diamond, but it does not resell
like an investment.

10

Hardness (Mohs)

2.42

Refractive index

D–F

Our colors

IGI

or GIA from 0.5 ct

## Lab-grown, lab-created, synthetic diamond: what is it?

These expressions all describe the same stone: a **diamond created in a laboratory**.
You will also see “lab diamond” or “man-made diamond”. In France, where we are based,
the regulations on the gemstone trade (decree no. 2002-65 of 14 January 2002) require
the word **“synthetic”** to accompany the name of the stone: a jeweler must therefore
write “synthetic diamond”, and may add “created in a laboratory”.

Calling it an “artificial” or “fake” diamond is misleading if it suggests an imitation:
a lab-grown diamond is not a fake. It has the composition (crystallized carbon),
the crystal structure and the physical and optical properties of a natural diamond.
The real imitations are cubic zirconia or glass, which are much softer. Moissanite
is a different gemstone, with its own properties: we compare the two in our guide
[moissanite vs diamond](https://www.simattabijoux.com/en/moissanite-vs-diamond/).

![La Marquisette lab-grown diamond ring worn, hand holding a bouquet of white ranunculus](
https://www.simattabijoux.com/wp-content/uploads/2026/10/bague-la-marquisette-portee-
bouquet-768x768.webp)

[La Marquisette](https://www.simattabijoux.com/en/collection/marquise-engagement-ring-gold/)
ring: a 1.2-carat oval lab-grown diamond framed by delicate marquise stones.

## How is a lab-grown diamond made?

The first synthetic diamond was produced in 1954, in the United States, for industrial
use. It was not until the 2010s that quality and sizes became commonly suitable 
for fine jewelry. Two processes are used today ([synthetic diamond on Wikipedia](https://en.wikipedia.org/wiki/Synthetic_diamond)):

### High pressure, high temperature

The conditions found more than 150 km below the surface are reproduced. A tiny diamond
seed is placed in a press with carbon, at around 1,400 °C and 50,000 times atmospheric
pressure. The carbon melts into a metal bath, then crystallizes on the seed.

In both cases, the result is a rough diamond, which is then cut and polished exactly
like a natural diamond (brilliant, oval, pear, marquise cut…). The process does 
not affect the beauty of the stone: an HPHT diamond and a CVD diamond of the same
quality are equally beautiful. The certificate also states which method was used.

## Lab-grown diamond vs natural diamond: the comparison

Composition

Pure carbon

Origin

Created in a laboratory, in a few weeks

Hardness (Mohs)

10

Refractive index (brilliance)

2.42

Dispersion (“fire”)

0.044

Density

3.52

Visible difference

None

Certificate

IGI or GIA (“laboratory-grown”)

Mining

No

Price

€€

Resale value

Low

## How can you tell a lab-grown diamond apart?

With the naked eye, it is impossible, and a jeweler with a loupe cannot do it either.
Standard diamond testers (thermal or electrical) identify it as a diamond, because
it is one. Only laboratory equipment (spectroscopy, ultraviolet imaging) reveals
the tiny traces left by growth in a laboratory.

For the buyer, the simplest guarantee is therefore the **certificate**: it always
states that the stone is a laboratory-grown diamond. On certified stones, the certificate
number is usually laser-inscribed on the girdle (the thin edge of the stone), invisible
to the naked eye but readable under a loupe.

## The certificate and the 4Cs: how to read a diamond’s quality

A lab-grown diamond is graded exactly like a natural diamond, according to the “
4Cs”:

Carat

the weight (1 carat = 0.2 g). A 1-carat round diamond measures about 6.5 mm in diameter.

Color

from D (perfectly colorless) to Z (visible yellow tint). From D to F, the diamond
is called colorless.

Clarity

from FL (flawless) to I (inclusions visible to the naked eye), through VVS (very,
very slightly included) and VS (very slightly included), both invisible to the naked
eye.

Cut

the quality of the proportions and polish, which creates the stone’s sparkle.

The two major laboratories that certify lab-grown diamonds are the **IGI** (International
Gemological Institute) and the **GIA** (Gemological Institute of America). Our lab-
grown diamonds are graded **D to F in color and VS to VVS in clarity**, meaning 
colorless and of very high clarity, and come with an IGI or GIA certificate from
0.5 carat.

![French Riviera tennis bracelets in white gold and lab-grown diamonds worn on the
wrist](https://www.simattabijoux.com/wp-content/uploads/2026/04/5678adbf-1f61-47fe-
9da7-7d8ca2e9c07e-1-768x768.jpeg)

[French Riviera Gold](https://www.simattabijoux.com/en/collection/lab-grown-diamond-tennis-bracelet-gold/)
tennis bracelets in lab-grown diamonds, from 1 to 10 carats.

## Lab-grown diamond price: why is it less expensive?

For the same carat, color and clarity, a lab-grown diamond costs **several times
less** than a natural diamond. There is no mine to operate and no long chain of 
intermediaries, and production has grown considerably: prices have dropped sharply
in recent years. In practice, the same budget buys a larger or higher-quality stone,
or a piece in gold rather than silver.

The price depends mainly on the 4Cs and the metal. On our product pages, you choose
the carat, the metal (9k, 14k or 18k gold, or 925 silver depending on the model)
and the color of the gold: the price of each version appears instantly. Try it, 
for example, with [La Solitaire ring](https://www.simattabijoux.com/en/collection/solitaire-ring-gold/)
or the [Double Éclat stud earrings](https://www.simattabijoux.com/en/collection/moissanite-stud-earrings-double-eclat/),
available in lab-grown diamond and in moissanite.

**Good to know**: a lab-grown diamond is not an investment. As prices fall and production
is not limited, its resale value is low. A natural diamond, too, usually resells
well below its purchase price. You choose a lab-grown diamond to wear it, not to
resell it.

## A diamond without mining

A lab-grown diamond does not come out of any mine: its origin is known and traceable,
from the laboratory to the jewel. This is one of the reasons why we place lab-grown
diamonds and moissanite at the heart of our creations. For natural diamonds, mining
conditions can be difficult to trace.

## A lab-grown diamond engagement ring?

More and more couples choose a lab-grown diamond for their engagement ring: it is
a real diamond, as strong and brilliant as a natural one, made to be worn every 
day for a lifetime. The price difference often allows a more beautiful stone, or
an 18k gold setting.

Our [La Solitaire ring](https://www.simattabijoux.com/en/collection/solitaire-ring-gold/)
holds a single round stone on six fine prongs, from 0.2 to 3 carats, in 925 silver
or in 9k, 14k or 18k gold. [La Marquisette](https://www.simattabijoux.com/en/collection/marquise-engagement-ring-gold/)
pairs a 1.2-carat oval diamond with delicate marquise stones, in white, yellow or
rose gold. For a custom-made project, [write to us](https://www.simattabijoux.com/en/contact-us/):
we will help you choose the size, quality and setting.

## Our lab-grown diamond jewelry

[⌊French Riviera Gold⌉⌊French Riviera Gold⌉French Riviera Goldthe tennis bracelet, a continuous line of lab-grown diamonds set in gold, from 1 to 10 carats.](https://www.simattabijoux.com/en/collection/lab-grown-diamond-tennis-bracelet-gold/)
[⌊Heart Catcher⌉Heart Catchera bracelet of heart-shaped lab-grown diamonds, in white, yellow or rose gold.](https://www.simattabijoux.com/en/collection/heart-catcher-bracelet-gold/)
[⌊L'Envolée Solitaire⌉L’Envolée Solitairea fine gold bracelet with a single diamond from 0.1 to 2 carats.](https://www.simattabijoux.com/en/collection/solitaire-diamond-bracelet-gold/)
[⌊Larmes d'Aurore⌉Larmes d’Auroregold drop earrings ending in pear-cut lab-grown diamonds.](https://www.simattabijoux.com/en/collection/lab-grown-diamond-drop-earrings-gold/)
[⌊Double Éclat⌉Double Éclatstud earrings in brilliant or Portuguese cut, from 0.2 to 8 carats per pair.](https://www.simattabijoux.com/en/collection/moissanite-stud-earrings-double-eclat/)
[⌊La Solitaire⌉La Solitaire](https://www.simattabijoux.com/en/collection/solitaire-ring-gold/)
[⌊La Marquisette⌉La Marquisette](https://www.simattabijoux.com/en/collection/marquise-engagement-ring-gold/)

![Larmes d'Aurore drop earrings in white gold and lab-grown diamonds, worn in the
evening](https://www.simattabijoux.com/wp-content/uploads/2026/10/boucles-oreilles-
larmes-aurore-or-blanc-portee-soiree-v2-768x768.webp)

[Larmes d’Aurore](https://www.simattabijoux.com/en/collection/lab-grown-diamond-drop-earrings-gold/)
earrings, in pear-cut lab-grown diamonds.

## Caring for a lab-grown diamond

Like any diamond, it hardly scratches and does not tarnish. However, lotion, soap
and dust eventually cloud any stone: a bath of warm soapy water and a soft toothbrush
restore all its sparkle. Take off your jewelry for sports, gardening or housework:
even a diamond can chip from a sharp knock on an edge.

## Frequently asked questions

Are lab-grown diamonds real diamonds?

Yes. A lab-grown diamond has the same composition (pure carbon), the same hardness
and the same sparkle as a natural diamond. Only its origin differs, and it must 
be disclosed as “synthetic” or “laboratory-grown”.

Does a lab-grown diamond turn yellow or lose its sparkle over time?

No. Its color and sparkle are stable, just like a natural diamond’s. If it looks
less brilliant, it simply needs cleaning.

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

Not with the naked eye, nor with a standard diamond tester. Only an equipped laboratory
can. The certificate always states the nature of the stone.

What is the difference between a lab-grown diamond and moissanite?

A lab-grown diamond is a diamond; moissanite is a different stone (silicon carbide),
slightly less hard, with more colorful flashes and a lower price. Everything is 
explained in our guide [moissanite vs diamond](https://www.simattabijoux.com/en/moissanite-vs-diamond/).

Does a lab-grown diamond have resale value?

It is low: it is not an investment. A natural diamond, too, generally resells well
below its purchase price.

Are your lab-grown diamonds certified?

Yes, from 0.5 carat, our lab-grown diamonds come with an IGI or GIA certificate.
They are graded D to F in color and VS to VVS in clarity.

A custom-made project?

Size, quality, setting: we will advise you on your piece.

[Write to us](https://www.simattabijoux.com/en/contact-us/)