4Cs of Lab-Grown Diamonds | Complete Buying Guide | Brilliance Culture

Diamond Education

The 4 C's of
Lab-Grown Diamonds

Every diamond — whether formed over billions of years underground or grown in a laboratory — is evaluated on the same four universal standards. Understanding the 4 C's helps you choose a stone that's right for you.

Every Diamond, IGI Certified
All Brilliance Culture lab-grown diamonds come with an IGI (International Gemological Institute) certificate — the global gold standard for diamond grading. Your certificate details the exact Cut, Colour, Clarity, and Carat of your stone, giving you complete transparency and lasting peace of mind.
01
Cut
Diamond cut inspection under loupe
Cut Grade
The Most Important C

The beauty of a diamond is defined by its cut

Cut is the single most important factor in how your diamond looks. It refers not to the shape, but to the precision of its proportions, symmetry, and polish — how expertly its facets are aligned to capture and return light as brilliance, fire, and scintillation.

A perfectly cut diamond reflects light back through the top like a mirror. A poor cut leaks light through the sides and bottom, making the stone appear dull regardless of its colour or clarity. No other C can compensate for a compromised cut.

Brilliance Culture Standard Every diamond we offer is Excellent Cut — the highest grade on the IGI scale. We only ever recommend Excellent Cut diamonds. This is non-negotiable at Brilliance Culture.
Excellent
Maximum brilliance, fire & scintillation
BC Standard
Very Good
Outstanding light performance
Good
Bright, with some light leakage
Fair / Poor
Noticeably reduced brilliance
Always Prioritise Cut Always choose Excellent Cut first — before colour, before clarity, before carat. A larger diamond with a poor cut will never outshine a smaller diamond with an Excellent cut.
02
Colour
Diamond colour grading
Colour Grade
The Absence of Colour

How pure and white your diamond appears

The IGI colour scale runs from D (completely colourless) to Z (noticeable yellow or brown tint). The less colour a diamond has, the rarer and more valuable it is. Lab-grown diamonds are graded on the exact same colour scale as mined diamonds.

In white gold or platinum settings, D–F grades offer the purest, iciest look. E colour is our recommendation — it sits at the finest end of near-colourless, offering exceptional purity and brilliant value.

Brilliance Culture Recommendation We recommend E colour — the sweet spot between absolute rarity and outstanding value. All our diamonds are E or above.
D
Absolutely colourless — the rarest grade
Premium
E
Colourless — near identical to D
BC Pick
F
Colourless — exceptional quality
Recommended
G – H
Near colourless — eye-clean in most settings
I – Z
Visible tint — not recommended
Our Recommendation D–F are all colourless grades — the difference between them is imperceptible to the naked eye. E gives you colourless quality at its finest, and is our preferred recommendation across all Brilliance Culture pieces.
03
Clarity
Diamond clarity and craftsmanship
Clarity Grade
Internal Purity

The presence of natural inclusions

Clarity measures the presence of inclusions (internal characteristics) and blemishes (surface marks) within a diamond. Even lab-grown diamonds can develop minor inclusions during the growth process — this is completely natural and expected.

What matters most is whether inclusions are visible to the naked eye. An "eye-clean" diamond — where no inclusions are detectable without magnification — is the ideal balance of beauty and value.

Brilliance Culture Recommendation VVS2 to VS1 is our sweet spot — eye-clean, beautifully pure, and outstanding value. We do not recommend below VS1.
FL / IF
Flawless / Internally Flawless — rarest
VVS1
Very very slight — nearly perfect
VVS2
Eye-clean — exceptional purity
BC Pick
VS1
Very slight — fully eye-clean
BC Pick
VS2
Eye-clean in most cases
Acceptable
SI1 – I3
Inclusions may be visible — not recommended
The Sweet Spot VVS2 and VS1 are indistinguishable to the naked eye. They give you a diamond that looks absolutely flawless while being significantly more accessible than FL or VVS1 grades.
04
Carat
Diamond carat size comparison on hand
Carat Weight
Lab-Grown Advantage Lab-grown diamonds give you a significantly larger stone for the same budget as a mined diamond. Always prioritise Excellent Cut over maximum carat — a well-cut smaller stone will always outshine a larger, poorly-cut one.
Weight & Size

How much your diamond weighs

Carat is the unit of weight used for diamonds — 1 carat equals 0.2 grams. Larger diamonds are rarer and therefore more valuable. However, two diamonds of identical carat weight can look very different depending on their cut, shape, and how they are set.

Because lab-grown diamonds are created in controlled environments, larger carat sizes are far more accessible without compromising on quality or certification.

CaratDiameterRelative Size
0.5 ct
~5.1 mm
1.0 ct
~6.4 mm
1.5 ct
~7.3 mm
2.0 ct
~8.1 mm
3.0 ct
~9.3 mm
4.0 ct
~10.2 mm
05
Certification
IGI Lab-Grown Diamond Certificate
IGI Certificate
Your Diamond's Identity Card

Your confidence, on paper

A diamond certificate is an independent, expert assessment of your diamond's quality — issued by a recognised gemological laboratory. It's not just a document; it's your assurance that the diamond you're buying is exactly what it claims to be.

Every Brilliance Culture diamond is certified by the IGI — the International Gemological Institute — the world's leading authority on lab-grown diamond grading.

Complete 4 C's breakdown — Cut, Colour, Clarity, and Carat weight, graded independently by IGI experts.
Lab-grown origin confirmed — Your certificate explicitly states the diamond is laboratory grown, so you know exactly what you own.
Unique report number — Each certificate carries a unique IGI report number, which can be verified online at any time for complete transparency.
Resale & insurance ready — An IGI certificate is globally recognised and accepted by insurers and jewellers worldwide, protecting the long-term value of your piece.
Included with every purchase — Your IGI certificate is delivered with your Brilliance Culture jewellery at no additional cost.
Why Lab-Grown

Same Diamond.
Smarter Choice.

Lab-grown diamonds are physically, chemically, and optically identical to mined diamonds. Graded on the exact same 4 C's by IGI. The only difference is their origin, their footprint, and their price.

Identical Quality
Same hardness, brilliance, and chemical composition as mined diamonds. Real diamonds, every time.
IGI Certified
Every stone independently graded and certified by the International Gemological Institute.
Better Value
Get a significantly larger, higher-grade diamond for the same investment as a mined stone.

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Our team is here to help you navigate every C and find the stone that's right for you.

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