Key Takeaways
- Scientists produce lab-grown diamonds under controlled laboratory conditions while preserving the same physical, chemical, and optical properties as natural diamonds.
- Advanced gemological testing helps experts identify lab-grown diamonds from natural diamonds with accuracy.
- CVD and HPHT technology produce lab-grown diamonds, and each method creates different growth characteristics.
- The diamond certification report verifies a diamond’s origin, discloses any treatments, and improves transparency for buyers.
- Solitaire Gemological Laboratories accurately identifies and certifies natural and lab-grown diamonds using advanced screening technologies like DiaScreen.
Introduction
The diamond industry has undergone a significant transformation with the introduction of laboratory-grown diamonds. These diamonds have made diamond ownership more accessible to a broader range of consumers by offering an alternative to natural diamonds without compromising on beauty, brilliance, or durability.
Laboratory-grown diamonds possess the same chemical composition, crystal structure, hardness, and optical properties as natural diamonds. The primary difference lies in their origin. Natural diamonds are formed deep within the Earth over billions of years, while laboratory-grown diamonds are produced in controlled manufacturing environments over several weeks using advanced technological processes.
As laboratory-grown diamonds become increasingly common in the jewellery market, accurate identification and transparent disclosure have become essential. Modern gemological laboratories employ sophisticated screening and analytical techniques to distinguish natural diamonds from laboratory-grown diamonds, ensuring confidence for consumers, retailers, and manufacturers.
What Are Lab-Grown Diamonds?
Laboratory-grown diamonds are genuine diamonds composed of crystalline carbon. They exhibit the same physical, chemical, and optical characteristics as natural diamonds and are graded using the same internationally recognised standards for colour, clarity, cut, and carat weight.
The key distinction is their formation.
Natural diamonds crystallise approximately 140–200 kilometres beneath the Earth’s surface under extreme pressure and temperature over billions of years before being brought closer to the surface through volcanic activity.
Laboratory-grown diamonds are created by replicating the conditions necessary for diamond crystal growth using advanced manufacturing technologies. Although the production process simulates certain natural conditions, it does not exactly replicate the Earth’s geological environment.
To the naked eye, natural and laboratory-grown diamonds are visually indistinguishable. Their differences become apparent only through specialised gemological examination, which evaluates features such as crystal growth structures, trace impurities, fluorescence behaviour, internal strain patterns, and spectroscopic characteristics.
Lab-Grown Diamonds vs Natural Diamonds: Key Differences
While natural and lab-grown diamonds appear identical, their growth histories leave distinct characteristics that specialised laboratory testing can identify.
Feature | Natural Diamonds | Lab-Grown Diamonds |
Formation | Formed naturally over billions of years beneath the Earth’s surface | Created in controlled laboratory conditions within weeks |
Composition | Crystalline carbon | Crystalline carbon |
Appearance | Visually identical | Visually identical |
Growth Pattern | Natural crystal growth | Controlled growth patterns depending on the production method |
Identification | Requires advanced laboratory analysis | Requires advanced laboratory analysis |
Since visual inspection alone cannot determine a diamond’s origin, laboratories rely on multiple scientific techniques to identify whether a diamond is natural or laboratory-grown.
To learn more about how natural diamonds form and the characteristics that make them unique, read our guide on natural diamond formation.
How Lab-Grown Diamonds Are Created
Modern laboratory-grown diamonds are primarily produced using two advanced manufacturing methods.
Chemical Vapour Deposition (CVD)
The Chemical Vapour Deposition (CVD) process begins with a thin diamond seed crystal placed inside a vacuum chamber. Carbon-rich gases, typically methane mixed with hydrogen, are introduced into the chamber. Energy from microwaves or plasma breaks down the gases, allowing carbon atoms to deposit layer by layer onto the seed crystal, gradually forming a diamond.
CVD-grown diamonds often exhibit distinctive layered growth structures, internal strain patterns, and characteristic fluorescence responses that assist gemological laboratories during identification.
High Pressure High Temperature (HPHT)
The High Pressure High Temperature (HPHT) method recreates the high-pressure and high-temperature conditions required for diamond crystal growth. A diamond seed crystal is exposed to pressures of approximately 5–6 GPa and temperatures exceeding 1,300°C in the presence of a carbon source.
Depending on the manufacturing process, HPHT-grown diamonds may display characteristic growth sectors, metallic flux inclusions, fluorescence behaviour, and spectroscopic features that help distinguish them from natural diamonds.
The Science Behind Diamond Identification
One of the important aspects of diamond identification involves analysing trace impurities, particularly nitrogen.
Type Ib Diamonds
Type Ib diamonds contain isolated nitrogen atoms within their crystal lattice. They are extremely rare in nature but are frequently associated with certain HPHT-grown diamonds due to the manufacturing process. However, not all HPHT-grown diamonds are Type Ib.
Type IIa Diamonds
Type IIa diamonds contain little or no measurable nitrogen and are among the purest diamonds known. Many CVD-grown diamonds belong to this category, although some HPHT-grown and natural diamonds may also be Type IIa.
Because several famous natural diamonds are also Type IIa, diamond type alone cannot determine whether a diamond is natural or laboratory-grown. Laboratories therefore evaluate multiple characteristics before confirming origin.
How Laboratories Distinguish Natural and Lab-Grown Diamonds
Determining a diamond’s origin requires comprehensive scientific analysis rather than a single test.
Modern gemological laboratories use a combination of advanced analytical techniques, including:
- Fluorescence imaging
- Photoluminescence spectroscopy
- Fourier Transform Infrared (FTIR) spectroscopy
- UV-Visible spectroscopy
- DiamondView or advanced growth-structure imaging
- Microscopic examination
- Growth structure analysis
- Defect and impurity analysis
Each technique reveals different information about the diamond’s internal characteristics. By evaluating all available evidence together, gemologists can accurately determine whether a diamond is natural or laboratory-grown.
If you’re new to the topic, learn more about lab-grown diamonds and how they compare with natural diamonds.
Why Diamond Certification Matters
An independent diamond grading report provides confidence by documenting a diamond’s characteristics and origin according to recognised gemological standards.
During examination, laboratories assess:
- Colour
- Clarity
- Cut (where applicable)
- Carat weight
- Growth structures
- Trace impurities
- Fluorescence behaviour
- Spectroscopic characteristics
- Evidence of treatments or post-growth processing
Where applicable, the report also discloses treatments such as HPHT post-growth treatment or irradiation, providing transparency for buyers, retailers, and manufacturers.
Independent grading reports enable informed purchasing decisions and promote trust throughout the diamond supply chain.
If you’re purchasing a laboratory-grown diamond, a detailed lab-grown diamond report helps verify its origin, grading, and key characteristics giving you greater confidence in your purchase.
DiaScreen: Advanced Screening Technology from SGL
As part of its diamond screening process, SGL utilises DiaScreen. It is an advanced fluorescence imaging system designed to rapidly identify diamonds that exhibit characteristics commonly associated with laboratory-grown origin.
DiaScreen analyses fluorescence responses and growth-related patterns under controlled ultraviolet illumination. The system helps identify:
- Possible CVD-grown diamonds
- Possible HPHT-grown diamonds
- Unusual fluorescence behaviour
- Growth-related anomalies
- Diamonds requiring additional laboratory examination
DiaScreen serves as an efficient screening tool. Any diamonds flagged during screening undergo further evaluation using advanced spectroscopic instruments and detailed gemological analysis before a final conclusion is reached.
SGL's Commitment to Accurate Diamond Identification
At SGL, every diamond submitted for examination undergoes a comprehensive evaluation using advanced screening technology, specialised laboratory instrumentation, and expert gemological analysis.
The assessment includes examination of growth structures, fluorescence behaviour, spectroscopic characteristics, trace impurities, internal features, and indicators of post-growth processing where applicable.
By combining advanced technology with experienced gemologists, SGL provides reliable identification and transparent grading reports that help buyers, retailers, manufacturers, and the jewellery industry make informed decisions with confidence.
Conclusion
The growing presence of laboratory-grown diamonds has increased the importance of accurate identification, transparent disclosure, and independent laboratory grading.
Although natural and laboratory-grown diamonds share the same physical, chemical, and optical properties, their different growth histories produce subtle characteristics that can only be detected through specialised gemological analysis.
Through advanced screening technologies such as DiaScreen, comprehensive laboratory testing, and independent grading reports, SGL supports transparency and confidence across the diamond industry by ensuring that every diamond is accurately identified and transparently represented.
Learn more about SGL’s diamond reports to understand how independent certification helps verify a diamond’s identity, grading, and authenticity.
Shatrughan Vishwakarma
Shatrughan Vishwakarma is an experienced Gems & Jewellery professional with 12+ years of expertise in Quality Assurance, Quality Control, and Education. Recognized for his technical knowledge and mentorship, he is committed to advancing quality standards and nurturing future industry professionals.
