Understanding Laboratory-Grown Diamonds | Cordellier
A clear, objective guide to origin, growth methods, quality, IGI grading and the differences between laboratory-grown and natural diamonds.
Learn how laboratory-grown diamonds are created, how their quality is assessed, and how they compare with natural diamonds
— clearly, objectively and in practical terms.
Every Cordellier centre diamond is independently graded by IGI
and accompanied by its own grading report.
What Is a Laboratory-Grown Diamond?
A laboratory-grown diamond is a diamond crystal grown through a controlled technological process rather than formed naturally in the Earth. It begins with a small diamond seed. Carbon atoms then build
around that seed in a diamond crystal structure. Once grown, the rough diamond is cut and polished using the same fundamental craftsmanship applied to natural diamonds.
Laboratory-grown and natural diamonds are both crystalline carbon and have essentially the same chemical, physical and optical properties. They differ, however, in origin and growth history. Those differences leave features that a specialist gemological laboratory can identify with advanced instruments.
A laboratory-grown diamond is not cubic zirconia, moissanite or another diamond simulant. Simulants are different materials that may resemble a diamond but do not share its crystal structure and
properties.
A laboratory-grown diamond is a diamond with a laboratory origin
— not an imitation and not anatural diamond.
How Are Laboratory-Grown Diamonds Made?
Most gem-quality laboratory-grown diamonds are produced using one of two methods: Chemical Vapour Deposition (CVD) or High Pressure High Temperature (HPHT). Both begin with a diamond seed and provide the conditions in which carbon can crystallise as diamond, but they do so in different ways.
CVD: Chemical Vapour Deposition
A thin diamond seed is placed inside a vacuum chamber. A carbon-rich gas is introduced and activated into a plasma. Carbon atoms separate from the gas and gradually build on the seed in layers, forming a diamond crystal. Some CVD-grown diamonds may undergo post-growth treatment to adjust their colour.
HPHT: High Pressure High Temperature
A diamond seed, a carbon source and a metallic growth medium are placed inside a growth cell. High pressure and high temperature create the conditions in which carbon can dissolve and crystallise onto the seed. The resulting diamond is then cut and polished.
Neither method is automatically better. Growth method alone does not determine beauty or quality. The finished diamond should be considered through its crystal quality, any disclosed post-growth treatment,its cutting, proportions, finish and face-up appearance.
Is a Laboratory-Grown Diamond a Real Diamond?
Yes. In gemological terms, a laboratory-grown diamond is a diamond. It has the diamond crystal structure and the properties associated with diamond. It is also important to describe its origin accurately: a laboratory-grown diamond is not a natural diamond, and the laboratory-grown origin should always be disclosed clearly.
The two origins are not reliably distinguished by appearance alone. A trained gemologist uses specialist screening and testing equipment, together with an independent grading report, to establish whether a
diamond is natural or laboratory-grown.
What both origins share
- Diamond hardness: both rate 10 on the Mohs hardness scale, although any diamond can chip if struck at a vulnerable edge.
- Optical performance: both can display brightness, fire and scintillation. These depend strongly on cutting and proportions, not origin alone.、
- Quality variation: both can contain inclusions and show differences in colour, clarity, proportions and finish.
- Care: both can collect oil and residue during wear and benefit from appropriate cleaning and professional inspection.
Laboratory-Grown and Natural Diamonds: A Balanced Comparison
Laboratory-Grown and Natural Diamonds: A Balanced Comparison
| Consideration | Laboratory-grown diamond | Natural diamond |
|---|---|---|
| Identity | Diamond with a laboratory-grown origin. | Diamond with a natural geological origin. |
| Formation | Grown from a diamond seed under controlledtechnological conditions, generally over weeks. | Formed through geological processes deep withinthe Earth over an immense span of time. |
| Material | Crystalline carbon with essentially the sameprincipal chemical, physical and optical propertiesas natural diamond. | Crystalline carbon with the properties associatedwith diamond. |
| Appearance | A well-cut stone can look the same to theunaided eye. Origin requires specialist identification. | A well-cut stone can look the same to the unaided eye. Origin requires specialist identification. |
| Durability | 10 on the Mohs hardness scale; suitable foreveryday fine jewellery with proper care. | 10 on the Mohs hardness scale; suitable foreveryday fine jewellery with proper care. |
| Quality | Varies by cut, colour, clarity, carat weight,proportions and individual crystal characteristics. | Varies by cut, colour, clarity, carat weight,proportions and individual crystal characteristics. |
| Rarity | Production can be repeated and scaled; it doesnot have geological rarity. | Its natural origin and finite geological occurrence contribute to its rarity narrative and market position. |
| Price | Generally has a lower current retail price than a natural diamond with comparable headline characteristics. Prices change with supply andtechnology. | Generally has a higher current retail price,influenced by natural rarity, recovery, sorting and established market structures. |
| Future value | Future resale value is not guaranteed and may beaffected by continuing production and pricechanges. | Natural origin may support a different secondarymarket, but resale value and appreciation arenever guaranteed. |
| Environment | Impact varies with electricity source, equipment,input materials, cutting, polishing and transport. | Impact varies with mining method, land andwater management, labour and communitypractices, cutting, polishing and transport. |
| Meaning | May appeal for technological origin,contemporary choice and greater designflexibility within a budget. | May appeal for geological history, rarity,provenance and traditional symbolism. |
1. Shape and design
Shape determines the diamond’s outline and strongly influences the character of the jewellery. Round brilliant diamonds are known for a highly standardised approach to light performance. Oval, emerald,cushion, pear, radiant and other fancy shapes each create different proportions, movement and finger coverage.
2. Cut and light performance
Cut is not simply the shape. It describes how effectively the facets, proportions and finish work together with light. Look for balanced brightness, fire, scintillation and contrast rather than choosing by one number alone. Fancy shapes also require close attention to outline, facet pattern and any areas that remain consistently dark or transparent.
3. Carat weight and measurements
Carat measures weight, not visible size. Two diamonds with the same carat weight can face up differently because of their proportions and shape. Review millimetre measurements and the intended setting alongside carat weight.
4. Colour
The D-to-Z scale describes the presence of body colour in colourless to near-colourless diamonds. The preferred grade depends on the diamond’s shape, size, setting metal and personal sensitivity to warmth.A higher grade is not automatically the best use of every budget.
5. Clarity
Clarity is assessed under 10× magnification. Consider the size, position, relief and nature of the characteristics — and whether they are visible without magnification. An eye-clean diamond can be an intelligent choice even when it is not at the top of the clarity scale.
6. Tone, transparency and individual appearance
Headline grades do not describe every visual detail. Some laboratory-grown diamonds may show colour nuances, graining or transparency effects that deserve a direct visual review. Examine the diamond face-up, in motion and under more than one lighting condition whenever possible.
7. Independent documentation
Confirm that the grading report clearly identifies the laboratory-grown origin and matches the stone’s shape, measurements, carat weight and other characteristics. Review any comments concerning the growth method or post-growth treatment.
Understanding Your IGI Grading Report
What to look for
- Report number and report type.
- A clear description identifying the diamond as laboratory-grown or natural.
- Shape, cutting style and millimetre measurements.
- Carat weight, colour grade and clarity grade.
- Cut grade where applicable, together with polish and symmetry.
- Fluorescence and relevant comments.
- Growth method or post-growth treatment information when stated.
- A laser inscription reference when an inscription is present.
How to verify the report
1. Open the official IGI report verification page or scan the report’s QR code.
2. Enter the complete report number.
3. Match the online report to the document supplied with the diamond.
4. Where a girdle inscription is present, confirm that it corresponds to the report number under magnification.
An IGI grading report is an independent description of origin and quality characteristics. It is not a retail price appraisal, a warranty or a promise of future value.
Beyond the Grading Report
A grading report gives an essential, independent framework — but it cannot fully describe how a diamond looks in person. Two diamonds with the same headline grades may differ in proportions, facet pattern, inclusion placement, colour nuance, transparency and overall visual balance.
This is why Cordellier combines independent IGI grading with visual selection. We review how the diamond performs face-up, how it moves in light, how its proportions suit the design and which quality trade-offs are meaningful for the individual client.
The Cordellier selection process
1. Confirm the IGI report and laboratory-grown or natural origin.
2. Review proportions, polish, symmetry and finish.
3. Inspect face-up appearance, movement, tone and transparency.
4. Match dimensions and shape to the intended setting.
5. Explain the relevant trade-offs clearly before the client chooses.
Price, Rarity and Long-Term Value
Laboratory-grown diamonds generally have a lower current retail price than natural diamonds with comparable headline characteristics. This reflects differences in production, scalability, supply and market structure — not a different standard of hardness or an inability to create fine jewellery.
Natural diamonds generally command a higher retail price because geological rarity, recovery, sorting and established market structures form part of their value. For some clients, that rarity and history are central to the meaning of the purchase.
Prices and secondary-market demand can change for both origins. Neither a grading report nor a retailer can guarantee appreciation or future resale value. If resale, insurance replacement or estate planning is important, seek current, independent valuation advice for the specific piece.
Environmental and Sourcing Considerations
A diamond’s origin alone does not provide a complete environmental or ethical conclusion. Responsible comparison requires evidence about the actual supply chain rather than assumptions based on a category label.
For laboratory-grown diamonds, relevant factors include the source and amount of electricity, production efficiency, equipment and input materials, post-growth treatment, cutting and polishing, labour practices and transport. For natural diamonds, relevant factors include the mining method, land and water management, labour and community practices, traceability, cutting and polishing, and transport.
Broad claims such as “zero impact”, “always sustainable” or “automatically ethical” can be misleading without specific evidence. Cordellier’s approach is to communicate documented information and avoid universal claims that origin alone cannot support.
Which Diamond Origin Is Right for You?
A laboratory-grown diamond may feel right if you are drawn to a technological origin, want greater flexibility in size or quality within a defined budget, or prefer to place more of the budget into the design and craftsmanship of the finished piece.
A natural diamond may feel right if geological origin, rarity, provenance and traditional symbolism are central to what the jewellery represents for you.
Neither choice is more meaningful by definition. Meaning comes from the person, the occasion, the design and the way the piece becomes part of a life.
Choose with Clarity
Cordellier offers laboratory-grown diamond jewellery and natural-diamond bespoke commissions. Our private consultation focuses on the design, the diamond’s documented characteristics, its origin, your budget and how the finished piece will be worn.
We will explain the relevant trade-offs and help you compare individual diamonds without asking you to accept a one-size-fits-all answer.
Frequently Asked Questions
Are laboratory-grown diamonds real diamonds?
Yes. They are diamonds with a laboratory grown origin. They have the diamond crystal structure and essentially the same principal chemical, physical and optical properties as natural diamonds. They are not diamond simulants.
Are laboratory-grown and natural diamonds exactly the same?
They share the principal properties associated with diamond, but they are not identical in origin or growth history. Advanced gemological testing can identify growth-related differences.
Can I tell the difference by looking at them?
Not reliably. A well-cut laboratory-grown diamond and a well-cut natural diamond can appear the same to the unaided eye. Specialist laboratory equipment is used to establish origin.
Are laboratory-grown diamonds as durable as natural diamonds?
Both rate 10 on the Mohs hardness scale and are suitable for everyday fine jewellery. Hardness does not make a diamond indestructible; either origin can chip if struck at a vulnerable edge.
Will a laboratory-grown diamond become cloudy?
The diamond material does not become cloudy simply because it was laboratory grown. Oil, cosmetics and residue can reduce sparkle on any diamond and should be removed through appropriate cleaning.
Are all laboratory-grown diamonds flawless?
No. Laboratory-grown diamonds can contain inclusions, graining and other growth-related features. They vary in colour, clarity, cutting and overall appearance just as individual natural diamonds do.
Is CVD better than HPHT?
Not automatically. Both methods can produce gem-quality diamonds. The growth method should be considered together with any treatment disclosure, cutting, proportions, transparency, colour and the individual stone’s appearance.
Are laboratory-grown diamonds always more sustainable?
No universal conclusion can be made from origin alone. Environmental performance depends on the specific producer, electricity source, equipment, materials, cutting, polishing and transport.Natural diamond impacts also vary by mine and supply chain.
Do Cordellier diamonds come with an IGI report?
Yes. Every Cordellier centre diamond is independently graded by IGI and accompanied by its own grading report.
Does an IGI report guarantee value?
No. The report independently documents origin and quality characteristics. It is not a price appraisal, investment promise or guarantee of future resale value.
Can a laboratory-grown diamond become an heirloom?
Yes. Its physical durability allows it to be worn and passed on. Whether it becomes an heirloom is a matter of personal history and meaning, not geological origin alone.
