What is a synthetic diamond?

Introduction: The synthetic diamond revolution

The jewelry world is undergoing a true revolution today with the rise of synthetic diamonds. These gemstones, created by humans in state-of-the-art laboratories, are challenging our traditional perceptions of diamonds and opening new opportunities for both consumers and the industry. While natural diamonds have fascinated humanity for millennia, synthetic diamonds represent the culmination of decades of scientific research and technological innovation.

Since 1954, the year that marked the history of synthetic diamonds with the creation of the first official diamond by Howard Tracy Hall, this technology has continued to evolve, achieving a quality now perfectly identical to that of natural diamonds. This breakthrough raises fundamental questions about value, authenticity, and ethics in the jewelry sector, while offering innovative alternatives for consumers who prioritize sustainability and ethical sourcing.

Definition and composition of the synthetic diamond

A synthetic diamond, also known as a lab-grown diamond, cultured diamond, or synthetic diamond, is a gemstone produced in a laboratory using advanced technological methods. Unlike simulated diamonds such as cubic zirconia or moissanite, a synthetic diamond has exactly the same chemical composition, the same crystal structure, and the same physical properties as a natural diamond.

Composed of more than 99.95% pure carbon, the synthetic diamond features:

• The same hardness : 10 on the Mohs scale, making it the hardest known material
• The same brilliance : identical refractive index of 2.42
• The same density : 3.52 g/cm³
• The same thermal properties : exceptional thermal conductivity

The only fundamental difference lies in their origin: while natural diamonds form deep in the Earth’s mantle over millions of years under extreme pressure and temperature conditions, synthetic diamonds are created in just a few weeks in specialized laboratories. This chemical difference between natural and synthetic diamonds is limited solely to the formation process, because at the molecular level, they are perfectly identical. These identical properties explain why it is impossible to distinguish a synthetic diamond from a natural diamond by sight—only specialized instruments can reveal their different origin.

Synthetic diamond manufacturing methods

There are currently two main methods for creating synthetic diamonds. Each method uses a different approach to reproduce the natural conditions of diamond formation, making it possible to obtain stones with specific characteristics.

Properties and characteristics of synthetic diamonds

Synthetic diamonds have all the remarkable properties that have made natural diamonds renowned:

Physical properties

• Exceptional hardness : 10 on the Mohs scale, maximum scratch resistance
• Unmatched brilliance : Refractive index of 2.42 creating a unique sparkle
• Thermal conductivity : Excellent conductivity, higher than copper
• Chemical stability : Exceptional resistance to corrosion and acids

Optical properties

• Light dispersion : Ability to split white light into a rainbow
• Fluorescence : Possible reaction under UV light depending on the production method
• Transparency : Perfect light transmission in higher grades

These remarkable properties mean that synthetic diamonds have traditionally been assessed using the same criteria as natural diamonds: the well-known 4Cs (Carat, Cut, Color, Clarity). However, a recent development deserves highlighting: the GIA (Gemological Institute of America) has recently adjusted its grading criteria because synthetic diamonds often display exceptional quality, sometimes superior to natural diamonds. Indeed, synthetic diamonds can reach levels of purity and crystalline perfection rarely found in nature, which has required a revision of grading standards. Nevertheless, most other certification laboratories continue to apply the same grading criteria to both types of diamonds.

Differences between a natural diamond and a synthetic diamond

Although chemically and physically identical, several factors distinguish natural diamonds from synthetic diamonds:

Differences in origin and formation

• Formation time : Millions of years for natural diamonds vs a few weeks for synthetic diamonds
• Formation conditions : Natural geological process vs a controlled laboratory environment
• Environmental impact : Intensive mining extraction vs laboratory production with a controlled footprint
• Societal aspects : Risks related to mining working conditions vs skilled technology-sector jobs
• Traceability : Origin sometimes difficult to establish vs full traceability of production

Detectable technical differences

• Specific inclusions : Natural diamonds contain unique geological inclusions, while lab-grown stones may show traces linked to their production method
• Growth patterns : A slightly different crystal structure visible under a specialized microscope
• Fluorescence response : Some lab-grown diamonds show distinct behavior under UV light (but not all)
• Spectroscopic analysis : A different molecular signature detectable only with advanced scientific equipment

Differences in perception and impact

Regarding the price of lab-grown vs natural diamonds, lab-grown diamonds generally cost 30 to 50% less, which often raises the question: does a lab-grown diamond lose value? For diamonds under 3 carats and classic white diamonds—whether natural or lab-grown—the question of financial investment generally does not arise. Gold remains the true investment asset in fine jewelry.

From an ethical standpoint, the ethical and eco-friendly lab-grown diamond offers significant advantages. These stones eliminate concerns related to “conflict diamonds” and provide a substantial reduction in environmental and social impact. The environmental impact of lab-grown diamonds is considerably lower compared with traditional mining, although production remains energy-intensive.

It is crucial to understand that lab-grown diamonds are genuine diamonds in every respect, not imitations. This distinction is essential to know how to identify a genuine lab-grown diamond: unlike simulants such as cubic zirconia, moissanite, or glass, which try to replicate a diamond’s look using different materials, lab-grown diamonds have exactly the same chemical composition and the same crystal structure as natural diamonds. To tell real diamonds from fake ones, professionals rely on precise criteria: hardness, thermal conductivity, refractive index, and molecular structure. On all these points, lab-grown diamonds perfectly meet the characteristics of a “real” diamond. The only difference lies in their formation process: one takes place in high-tech laboratories, the other deep within the Earth.

Fancy-color diamonds: The chromatic revolution

One of the most fascinating aspects of lab-grown diamonds lies in their ability to replicate—and even surpass—nature when it comes to color. While natural fancy-color diamonds are among the rarest and most expensive gemstones in the world, synthesis opens up an entirely new chromatic universe, making these colorful marvels more accessible.

The exceptional rarity of natural fancy-color diamonds

In nature, fancy-color diamonds are exceedingly rare. A gem-quality natural pink diamond accounts for only 0.01% of global production, while a natural green diamond is even more exceptional. These colors result from highly specific geological anomalies: the presence of chemical impurities, exposure to natural radioactivity, or particular crystal distortions that occurred during their formation over millions of years.

This extreme rarity explains why natural fancy-color diamonds reach astronomical prices at auction. In 2017, the 59.60-carat "Pink Star" pink diamond sold for $71.2 million, setting a world record.

Technological mastery of synthetic colors

Lab-grown diamonds are transforming the landscape by making it possible to create colors in a controlled, repeatable way. Scientists can now "program" a diamond’s color by adding specific elements during the growth process :

Full palette of available colors

• Pink diamonds : Obtained through a specific heat treatment or under particular growth conditions. These gemstones offer all the romance and elegance of natural pink diamonds, perfect for creations such as the Loop pear-shaped pink diamond ring. Discover all the secrets of these exceptional gemstones in our guide to the magic of pink diamonds

• Green diamonds : Created through controlled exposure to certain types of radiation or by incorporating specific impurities. This color, exceptionally rare in nature, becomes accessible through synthesis. Our article on the rarity of the green diamond explores this fascinating color in detail
• Blue diamonds : Produced by incorporating boron into the crystal lattice. These diamonds faithfully recreate the beauty of legendary natural blue diamonds such as the Hope Diamond
• Yellow diamonds : Created by the controlled addition of nitrogen during growth. From pale yellow to vivid canary yellow, a full spectrum of shades becomes possible
• Orange, champagne, and cognac diamonds : Obtained through various combinations of impurities and treatments, offering warm, sophisticated hues

Revolutionary advantages of lab-grown colored diamonds

Affordability

The main advantage of lab-grown colored diamonds lies in their price. While a 1-carat natural pink diamond can cost between €50,000 and €500,000 depending on its quality, an equivalent lab-grown pink diamond will be available between €3,000 and €15,000. This price difference allows a much wider audience to access the beauty of colored diamonds.

Quality and intensity control

Synthesis enables precise control over color intensity. Laboratories can produce diamonds with perfectly saturated, uniform colors, often more intense than their natural counterparts. This technical mastery ensures a level of consistency impossible to achieve with natural stones.

Creating matching sets

Thanks to production control, it becomes possible to create perfectly matched sets: earrings with diamonds of identical color and intensity, or necklaces composed of harmonious chromatic gradations. This was nearly impossible with natural diamonds due to their rarity.

Innovation in contemporary jewelry

Lab-grown colored diamonds unleash the creativity of contemporary jewelers. They can now design bold pieces combining multiple colors, create spectacular color gradients, or offer bespoke creations featuring the client’s favorite color.

This democratization also makes colored diamonds accessible for everyday lab-grown diamond jewelry, such as colored diamond studs, turning these exceptional stones into attainable pleasures. For those wondering where to buy an ethical lab-grown diamond, specialized lab-grown diamond jewelry brands now offer a wide selection of responsible, traceable creations.

The diamond’s chromatic future

Ongoing research in the field of lab-grown diamonds is revealing even more extraordinary possibilities. Scientists are exploring new methods to create unprecedented colors, color-shifting effects depending on the lighting, and diamonds with special optical properties.

This chromatic revolution is redefining the aesthetic codes of modern fine jewelry, where color becomes a vehicle for artistic expression freed from the constraints of natural rarity. Synthetic colored diamonds do not merely imitate nature: they transcend it, offering designers and connoisseurs of fine gemstones a new visual language of unparalleled richness.

Detection and identification: Technologies and regulations

The growing sophistication of synthetic diamonds requires ever more advanced detection methods to distinguish their origin.

Professional detection methods

Professionals now use cutting-edge technologies to identify the origin of diamonds:

Advanced analytical techniques

• Photoluminescence spectroscopy : This technique analyzes each diamond’s unique "light signature" by studying how it responds to specific wavelengths
• Specialized microscopic examination : Observation of internal growth patterns that differ depending on origin
• UV fluorescence testing : Some synthetic diamonds display characteristic reactions under ultraviolet light
• Infrared spectroscopic analysis : Detection of impurities and specific molecular structures

Enhanced certification and traceability

As synthetic diamonds have become increasingly sophisticated and indistinguishable from natural diamonds, the certification industry has had to evolve rapidly. The stakes are critical: ensuring consumers receive a clear, reliable identification of their diamond’s origin, while maintaining confidence across the entire diamond market.

This adaptation proved necessary because traditional diamond grading methods could no longer distinguish synthetic stones from natural ones. Certification laboratories therefore developed new protocols, invested in state-of-the-art equipment, and trained their gemologists in the specific characteristics of synthetic diamonds.

Recognized certification bodies

Today, several leading international organizations offer specialized certification services for synthetic diamonds:

• GIA (Gemological Institute of America) : As the global leader in certification, the GIA pioneered the identification of synthetic diamonds. The institute issues dedicated reports clearly marked "Laboratory-Grown Diamond" and uses advanced analytical techniques to determine origin and production method
• IGI (International Gemological Institute): An internationally recognized certification body in more than 18 countries, IGI has developed strict protocols for identifying synthetic diamonds. Their certificates explicitly state the synthetic origin and include detailed information on the production method
• HRD Antwerp: A leading European authority in diamond certification, HRD Antwerp provides specialized certification reports for synthetic diamonds, ensuring accurate identification in line with European standards
• SCS-007 Standard: A specific international standard developed for synthetic diamonds, it guarantees not only traceability and quality, but also transparency in production processes and verification of ethical manufacturing conditions

Advanced traceability technologies

Beyond simple certification, synthetic diamonds now benefit from exceptional traceability. Unlike natural diamonds, whose origin can sometimes be difficult to establish, each synthetic diamond can be tracked from its creation through to its final sale.

This traceability includes precise data on the production method used, manufacturing conditions, the creation date, and sometimes even a microscopic laser inscription invisible to the naked eye but detectable by professionals. Some producers go as far as offering a "digital passport" for each diamond, accessible via QR code and containing the stone’s full history.

International regulations: Ensuring market transparency

With the rapid growth of synthetic diamonds, global authorities quickly recognized the need to establish strict regulatory frameworks. These regulations aim to protect consumers by ensuring clear, transparent information on the diamonds’ origin, while safeguarding confidence in the global diamond market.

French regulations

In France, the law requires clear identification, with the mandatory use of the terms "synthetic diamond" or "lab-grown diamond" in any sale or commercial presentation. This requirement applies to all jewelry professionals, from retail to public auctions.

International standards

The legislation on purchasing synthetic diamonds varies by country:

• United States : Since 2018, the FTC (Federal Trade Commission) has authorized the use of the term "diamond" for synthetic stones, provided their origin is clearly identified. Sellers must use qualifiers such as "laboratory-grown", "laboratory-created" or "synthetic"
• European Union : European directive requiring mandatory disclosure of synthetic origin in all commercial communications, thereby ensuring transparency for European consumers
• Germany : Particularly strict regulations, with enhanced labeling controls and significant penalties in the event of non-compliance
• ISO 18323 Standard : International standard defining identification and naming criteria, serving as a global reference for the industry

Conclusion

Lab-grown diamonds represent a major technological revolution that is redefining the codes of modern fine jewelry. By offering stones that are chemically and physically identical to natural diamonds, yet produced ethically and sustainably, they meet the expectations of a new generation of consumers who are mindful of social and environmental issues.

Whether for creating exceptional jewelry or exploring new color palettes, lab-grown diamonds open up unprecedented possibilities. Their ability to be produced to precise specifications, their full traceability, and their more accessible price point make them a credible and attractive alternative.

This transformation echoes the evolution of other luxury sectors that have undergone similar revolutions. The pearl industry perfectly illustrates this dynamic with the advent of Mikimoto cultured pearls at the beginning of the 20th century. Initially rejected by purists, these cultured pearls ultimately came to dominate the market, relegating natural pearls to the status of exceptional curiosities. Likewise, the fur industry saw the emergence of synthetic and alternative materials radically transform consumer habits, driven by ethical and environmental considerations similar to those motivating the adoption of lab-grown diamonds.

Today, the market is structured around two distinct segments that coexist harmoniously. On the one hand, exceptional diamonds—large natural stones of outstanding quality—retain their aura of rarity and their investment potential. On the other, for everyday fine jewelry diamonds, synthetics are rapidly gaining ground thanks to their attractive value for money. This split is reshaping commercial strategies: high jewelry houses maintain their positioning around exceptional natural stones, while mass-market jewelers are integrating lab-grown diamonds on a large scale into their collections.

For the care of your diamonds, whether natural or lab-grown, the same precautions apply to preserve their exceptional brilliance over time. Lab-grown diamond care and cleaning follows exactly the same protocols as for natural diamonds: regular cleaning with soapy water, and avoiding impacts and harsh chemicals. The future of the diamond industry is thus taking shape around a structured coexistence: exceptional stones (rare natural diamonds of large size and outstanding quality) will retain their status as unique geological treasures, while jewelry stones (diamonds intended for everyday jewelry and accessible creations) will see growing adoption of lab-grown diamonds, further enriching the fascinating world of gemstones.