Diamond Science & Certification

Lab-Grown Diamond Education

Everything you need to know before you buy — the science of how lab diamonds grow, how GIA certifies them, what the 4Cs really mean, and why they are physically identical to mined stones.

100%
Identical carbon chemistry
60–80%
More affordable than mined
10/10
Mohs hardness scale
2.42
Refractive index (identical)
Round brilliant cut lab-grown diamond — pure carbon, D colour, 10/10 Mohs hardness, 2.42 refractive index

Side by Side

Lab-Grown vs Mined Diamond

The science is unambiguous. The only difference is origin and price.

Property Mined Diamond Lab-Grown ✓
1ct Market Price€7,500–€12,000€1,800–€2,800-75%
Chemical CompositionPure Carbon (C)Pure Carbon (C)
Crystal StructureCubicCubic
Mohs Hardness10 / 1010 / 10
Refractive Index2.4172.417
Thermal Conductivity900–2,320 W/mK900–2,320 W/mK
GIA / IGI CertifiedGIAGIA & IGI
Conflict-Free OriginNot guaranteed100% Guaranteed
Full TraceabilityOften limitedComplete chain
Environmental FootprintSignificantDramatically lower
◆ GIA states: "Lab-grown diamonds are diamonds." They are graded using the same 4Cs system as natural diamonds.
Diamond cubic crystal lattice — pure carbon atoms in identical tetrahedral cubic structure, lab-grown or mined

The cubic crystal lattice of diamond — pure carbon in a tetrahedral arrangement — is physically identical whether formed deep in the earth over billions of years or in a laboratory over weeks.

GIA Grading System

The 4Cs of Diamond Quality

The universal language of diamond quality, developed by GIA. Every certified stone — lab or mined — is graded by these four criteria.

The 4Cs of Diamond Quality — Cut, Colour, Clarity, Carat — GIA grading system infographic
I

Cut

Cut is the most important of the 4Cs — it determines how brilliantly light performs in your diamond. A well-cut stone will outshine a poorly-cut stone of higher colour or clarity every time. GIA grades cut on five levels for round brilliant diamonds.

Excellent
Very Good
Good
Fair
Poor

All Grown Lab Diamond stones are Excellent or Very Good cut. Cut grade applies to round brilliants; fancy shapes are graded on Polish and Symmetry.

II

Colour

GIA grades diamond colour on a D–Z scale. D is completely colourless — the most desirable and rare. Colour differences between grades are subtle to the naked eye, but GIA-trained gemologists measure them under controlled lighting.

D
E
F
G
H
I
J
K
L
M
→Z
D–F · ColourlessG–J · Near ColourlessK–Z · Faint Yellow

Our lab diamonds typically achieve D–F (colourless) grades. CVD growth often produces Type IIa stones — the purest category, also attained by the world's most famous natural diamonds.

III

Clarity

Clarity refers to the presence of internal inclusions or external blemishes. GIA grades clarity across 11 grades using 10× magnification. Flawless (FL) stones are exceptionally rare. VS1–VS2 inclusions are invisible to the naked eye.

FL IF VVS1 VVS2 VS1 VS2 SI1 SI2 I1 I2 I3
FL / IF — Flawless or Internally Flawless. Rare & exceptional.
VVS1–VS2 — Very difficult to see even under magnification. Our minimum standard.
SI1–SI2 — Inclusions visible under 10× loupe but not to the naked eye.
I1–I3 — Inclusions visible to the naked eye. We do not offer these grades.
IV

Carat Weight

Carat is the unit of weight for diamonds. One carat equals exactly 0.2 grams, divided into 100 points. A 0.50ct diamond is a "50-pointer." While carat affects price significantly, cut quality determines how large a stone appears.

0.5
0.50ct
5.2mm
0.75
0.75ct
5.9mm
1.0
1.00ct
6.5mm
1.5
1.50ct
7.4mm
2.0
2.00ct
8.2mm
3.0
3.00ct
9.4mm

Lab-grown diamonds allow you to buy a significantly larger stone at the same budget as a mined diamond — without any compromise in quality or certification.

Two Methods, One Diamond

CVD vs HPHT

Both methods produce genuine, certifiable diamonds. Each has distinct characteristics that affect which stones we recommend for which rings.

CVD Method

Chemical Vapour Deposition

Plasma Chamber Growth

6–12
Weeks to grow
800°C
Growth temp.
Type IIa
Diamond type
  • A diamond seed crystal is placed in a chamber filled with carbon-rich gas (typically methane and hydrogen).
  • Microwave energy ionises the gas into a plasma, releasing carbon atoms that crystallise onto the seed layer by layer.
  • Growth happens at relatively low pressure, allowing exceptional control over crystal purity.
  • Produces Type IIa diamonds — the same category as the Cullinan and Koh-i-Noor. Only 2% of natural diamonds are Type IIa.
  • Ideal for D–F colourless stones and VS1+ clarity grades. Used in our Lumina, Aurora, Trilogie, Belle Époque, and Éclat rings.
CVD Chemical Vapor Deposition lab diamond growth process — plasma chamber diagram
HPHT Method

High Pressure High Temperature

Earth Simulation Growth

3–4
Weeks to grow
1,500°C
Growth temp.
50,000 atm
Growth pressure
  • Replicates the extreme conditions deep within Earth's mantle — over 50,000 atmospheres of pressure at 1,300–1,600°C.
  • A diamond seed is placed in a press with a carbon source (graphite) and a metal catalyst that dissolves the carbon and feeds crystal growth.
  • Growth is faster than CVD and can produce very large rough crystals suited to step cuts.
  • Produces excellent colourless stones and is the preferred method for our emerald and full-pavé rings where VS1 clarity is the minimum spec.
  • Used in our Rosée Pavé, Pureté Emerald, and Éternité Full Pavé rings.
HPHT High Pressure High Temperature lab diamond growth process — hydraulic press diagram
CVD
D–F colourless, Type IIa purity
VS
HPHT
Larger rough, step-cut ideal
Pressure
Low pressure plasma (~1 bar)
VS
Pressure
50,000+ atmospheres
Growth Time
6–12 weeks
VS
Growth Time
3–4 weeks (faster)
Result
Both are 100% genuine, GIA/IGI certifiable diamonds
=
Result
Both are 100% genuine, GIA/IGI certifiable diamonds

Independent Certification

The GIA Lab-Grown Diamond Grading Report

Every Grown Lab Diamond stone is independently graded by GIA or IGI. Your certificate travels with your ring — a permanent record of your stone's exact quality.

What is a GIA Lab-Grown Diamond Report?

GIA (Gemological Institute of America) began issuing Lab-Grown Diamond Grading Reports in 2019. The report uses the same 4Cs grading scales as natural diamonds — colour, clarity, cut, and carat weight — so you can directly compare quality across stones.

The report is issued after the stone is examined by multiple GIA-trained gemologists under controlled laboratory conditions. It is completely independent — GIA has no commercial relationship with the seller.

Each GIA lab-grown report carries a unique report number that is also laser-inscribed on the stone's girdle, along with the words "LABORATORY GROWN". This makes the stone permanently identifiable.

  • Colour Grade (D–Z) — Measured against master colour comparison stones under standardised lighting. D is colourless; the most desirable.
  • Clarity Grade (FL–I3) — 11-grade scale assessed at 10× magnification. FL is flawless; VVS1 and above are considered exceptional.
  • Cut Grade (Excellent–Poor) — Measures light performance: brilliance, fire, and scintillation. Applied to round brilliants; fancy shapes receive polish and symmetry grades.
  • Carat Weight — Measured to five decimal places and rounded to two. Noted on the report to the nearest hundredth.
  • Fluorescence, Polish & Symmetry — Additional quality indicators reported alongside the 4Cs.
  • Laser Inscription — The GIA report number and "LABORATORY GROWN" are permanently inscribed on the girdle — readable under 10× magnification.
  • QR Verification — Every report can be verified online at GIA's Report Check, confirming authenticity in seconds.

* Representative sample report. Each stone you purchase comes with its own original GIA or IGI certificate with unique report number matching your specific diamond.

GIA lab-grown diamond grading certificate with engagement ring — Colour D, Clarity VVS1, Cut Excellent

Your Certificate Explained

How to Read Your GIA Report

When your ring arrives, here is exactly what to look for on your certificate — and how to verify it is authentic.

1
🔢

Report Number

Every GIA report carries a unique numeric report number. This same number is laser-inscribed on your diamond's girdle. Check that the number on your certificate matches the inscription on your stone — they must be identical.

Verify at gia.edu/report-check
2
🏷️

Laboratory Grown Notation

GIA lab-grown reports are distinguished by a teal/blue colour scheme and carry the explicit notation "LABORATORY GROWN." The stone's girdle inscription also includes this text. This is mandatory — any authentic lab-grown GIA report will carry this.

Teal colour scheme = lab-grown report
3
✂️

Shape & Measurements

The report states the shape (e.g. Round Brilliant, Oval, Emerald) and exact measurements in millimetres. For round stones: minimum diameter – maximum diameter × depth. Verify these match your stone to confirm it is the certified stone.

E.g. 6.49–6.52 × 4.00 mm
4
🎨

The 4Cs Grades

The four main grades — Carat Weight, Colour Grade, Clarity Grade, and Cut Grade — appear prominently. A colour scale bar and clarity plot are also included, showing exactly where on each scale your stone falls and where inclusions are located.

D colour · VVS1 clarity = exceptional
5

Polish, Symmetry & Fluorescence

Additional quality grades appear below the 4Cs. Polish and Symmetry should ideally be Excellent or Very Good. Fluorescence is noted — None is most neutral. Strong blue fluorescence can sometimes make a stone appear milky in UV-rich lighting.

Excellent / Excellent / None = ideal
6
📱

QR Code Verification

Every GIA report includes a QR code that links directly to GIA's Report Check database. Scan it or visit gia.edu/report-check and enter your report number to verify the report is genuine and matches the details on your certificate.

Takes under 30 seconds to verify

From Seed to Setting

How Your Diamond Is Grown & Certified

Six to twelve weeks of precision science, then months of craftsmanship — before the ring reaches your hands.

1

Diamond Seed

A tiny diamond seed crystal — pure carbon — is placed in a precision CVD chamber or HPHT press. This seed determines the crystal's orientation and growth axis.

2

Crystal Growth

Over 6–12 weeks (CVD) or 3–4 weeks (HPHT), carbon atoms bond layer by layer into a perfect cubic crystal lattice — the same structure as a natural diamond formed over billions of years.

3

Cut & Polish

Master cutters analyse the rough crystal for maximum brilliance. Each stone is cut to precise proportions and polished to an Excellent finish, then laser-inscribed with its GIA or IGI report number.

4

GIA / IGI Grading

The stone is submitted — anonymously — to GIA or IGI. Multiple independent gemologists grade it, the report is issued, and the certificate is matched to the stone. This process takes 2–4 weeks.

The Science of Better

Why Choose Lab-Grown?

Real diamonds, created with technology instead of mining. Identical in every way that matters.

Chemically Identical

Pure carbon in a cubic crystal structure. Same Mohs hardness of 10, same refractive index of 2.417, same thermal conductivity. GIA themselves state that lab-grown diamonds are diamonds — not simulants, not imitations.

100%Identical carbon structure

Dramatically Affordable

Without the mining supply chain — no geological surveys, no extraction equipment, no complex international logistics — our diamonds cost 60–80% less than mined equivalents of the same certified quality. Your budget buys a dramatically better stone.

60–80%Lower than mined equivalent

Ethically Certain

No conflict zones. No environmental destruction. Complete origin traceability from seed crystal to certified stone. Every Grown Lab Diamond has a clean, fully documented origin — so your ring tells only a story of love.

ZeroConflict or mining impact

Common Questions

Frequently Asked

Are lab-grown diamonds real diamonds?
Yes — completely. Lab-grown diamonds have the same chemical composition (pure carbon), the same cubic crystal structure, and the same optical and physical properties as mined diamonds. The GIA and IGI certify them with the same rigorous standards and grading scales. GIA's official position is: "Lab-grown diamonds are diamonds." No gemologist using standard tools can tell the difference.
What is the difference between CVD and HPHT?
CVD (Chemical Vapour Deposition) grows diamonds from a carbon-rich gas plasma at relatively low pressure over 6–12 weeks, often producing exceptionally pure Type IIa stones with D–F colour. HPHT (High Pressure High Temperature) mimics earth's mantle conditions at 50,000+ atmospheres and 1,300–1,600°C, with a slightly faster growth cycle of 3–4 weeks. Both methods produce genuine, certifiable diamonds. The method is noted on the GIA certificate and does not affect the diamond's physical properties.
How does GIA grade lab-grown diamonds?
GIA uses the same 4Cs grading system as for natural diamonds: Colour (D–Z scale), Clarity (FL through I3, assessed at 10× magnification), Cut (Excellent through Poor for round brilliants), and Carat Weight. The stone is submitted anonymously and graded by multiple independent gemologists. The resulting Lab-Grown Diamond Grading Report is distinguished by its teal colour scheme and explicitly states "LABORATORY GROWN." The report number is laser-inscribed on the stone's girdle.
What does the colour grade D actually mean?
D is the highest colour grade on GIA's scale — it means the diamond is completely colourless when viewed face-down by a trained gemologist under standardised, controlled lighting. D–F grades are all considered "colourless." The difference between D and F is invisible to most people. G–J stones are "near colourless" and appear white when set in a ring. CVD lab-grown diamonds commonly achieve D–F grades because the growth process naturally produces very pure, colourless crystals.
Can a jeweller or gemmologist tell the difference?
No — not with standard tools. Lab-grown and mined diamonds are physically and chemically identical. Even experienced gemmologists using loupes, microscopes, spectroscopes, and refractometers cannot distinguish them. Only purpose-built laboratory instruments — such as the GIA iD100 or De Beers SYNTHdetect — can identify a lab diamond by detecting trace differences in crystal growth patterns. Your GIA certificate and laser inscription make the origin explicit without needing any testing.
Why are lab-grown diamonds 60–80% more affordable?
The price of a mined diamond reflects the entire supply chain: geological surveys, mining operations, water usage, land rehabilitation, transportation, customs, multiple intermediaries, and the rarity premium. Lab-grown diamonds bypass all of this. The only costs are the growth facility, energy, skilled labour for cutting, and certification. The saving is passed directly to you — the same certified stone, at a fraction of the price.
What clarity grade should I choose?
We recommend VS1 or above for most shapes. VS1 and VS2 stones have inclusions that are very difficult to see even under 10× magnification and completely invisible to the naked eye. For step cuts (emerald, Asscher) — where the open table acts like a mirror — we recommend VVS2 or higher, as the facet arrangement makes inclusions more visible than in brilliant cuts. All our rings are offered with VS1 minimum; we stock VVS1 and VVS2 for our emerald-cut Pureté ring.
What is the IGI and how does it differ from GIA?
IGI (International Gemological Institute) is the world's largest independent gem certification laboratory, based in Antwerp. Like GIA, IGI grades diamonds on the same 4Cs scale. IGI was one of the first labs to develop a specific grading system for lab-grown diamonds and is highly regarded in the lab-grown diamond industry. Both GIA and IGI certificates carry significant market recognition. Some jewellers find IGI grading slightly more generous than GIA for borderline clarity grades — we specify which lab certified each stone in every listing.

Ready to Choose Your Diamond?

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