The chemistry: why lab-grown diamonds are real diamonds
Diamond is a specific form of crystalline carbon, the hardest naturally occurring substance, with a face-centred cubic crystal structure where each carbon atom is covalently bonded to four neighbours in a tetrahedral arrangement. This crystal structure is what gives diamond its extraordinary hardness (10 on the Mohs scale, the maximum), its high refractive index (2.417, one of the highest for any transparent natural substance), and its exceptional thermal conductivity (higher than any metal) (GIA Gem Reference Guide, 2006 edition, pp. 8–12, Gemological Institute of America, Carlsbad).
A lab-grown diamond has exactly this crystal structure. The carbon atoms are arranged in exactly the diamond cubic lattice. The bonds between them are identical to those in a natural diamond. The physical and optical properties that result, hardness, refractive index, dispersion (0.044), thermal conductivity, electrical resistance, are identical to natural diamond within the measurement precision of standard gemological instruments.
The Federal Trade Commission (US) updated its Jewelry Guides in 2018 specifically to reflect this chemical equivalence, removing language that had previously defined "natural" as a required component of the word "diamond" (US FTC Jewelry Guides, 2018 revision, ftc.gov). The FTC's position, mirroring that of ISO 18323:2015, is that lab-grown diamonds are genuine diamonds but must be disclosed as lab-grown.
What is different from natural diamonds
If lab-grown diamonds are chemically identical to natural diamonds, what is actually different? Several things (GIA Gems & Gemology, various lab-grown diamond research articles; GIA Gem Reference Guide, 2006 edition):
Growth environment: Natural diamonds form at depths of approximately 150 to 200 kilometres in the earth's mantle, under temperatures of approximately 900°C to 1,300°C and pressures of approximately 45 to 60 kilobars (GIA Gem Reference Guide, 2006 edition, p. 9). Lab-grown diamonds form in reactors at temperatures and pressures recreating these conditions (HPHT) or in low-pressure plasma reactors (CVD).
Growth time: Natural diamonds took millions to billions of years to form. Lab-grown diamonds take between a few days and several weeks depending on the process and the desired size.
Growth patterns: The crystal growth patterns in lab-grown diamonds differ from natural diamonds in ways that are detectable by specialist equipment, specific spectroscopic signatures, fluorescence patterns, and strain patterns under polarised light. These are not visible to the naked eye or under a 10× loupe; they require scientific instruments. This is why GIA and IGI run screening instruments before grading every stone: to confirm natural or synthetic origin.
Trace elements and inclusions: Natural diamonds often contain trace elements (nitrogen, boron) and natural inclusions (other minerals trapped during growth) that reflect their geological environment. Lab-grown diamonds have different characteristic trace element profiles, CVD diamonds often have less nitrogen than typical natural diamonds; HPHT diamonds may show metallic flux inclusions from the growth process. These differences are diagnostically useful for identification but do not affect the diamond's optical or physical performance.
How lab-grown diamonds are made: CVD and HPHT
HPHT, High Pressure High Temperature
HPHT synthesis recreates the conditions under which natural diamonds form, extreme pressure and high temperature applied to carbon in the presence of a metallic catalyst (typically iron, cobalt, or nickel). The carbon feedstock dissolves in the molten metal catalyst and recrystallises as diamond around a small diamond seed crystal (GIA Gems & Gemology, "Laboratory-Grown Diamonds," various research articles; GIA DiamondCheck documentation).
The first HPHT synthesis of reproducible diamonds by General Electric researchers (Tracy Hall, Herbert Strong, and team) was announced in February 1955 after experiments beginning in 1954. The initial results were industrial-quality crystite, small, gritty crystals useful for abrasives but not for jewellery. GE's process was developed into industrial diamond production that still supplies a large proportion of the world's industrial diamond demand (historical documentation of GE's diamond synthesis, academic diamond science history).
Gem-quality HPHT diamonds, large, colourless, and of sufficient clarity for jewellery, became technically feasible in the 1990s and commercially significant in the 2000s. Modern HPHT diamond reactors can produce gems of multiple carats in several weeks.
CVD, Chemical Vapour Deposition
CVD diamond growth uses a completely different mechanism from HPHT. A diamond seed plate is placed in a low-pressure reactor chamber. A carbon-containing gas mixture (typically methane and hydrogen) is introduced and ionised by microwave energy or other plasma generation methods. The ionised carbon radicals deposit as diamond atoms on the seed plate, growing layer by layer at relatively low pressures and moderate temperatures (GIA Gems & Gemology research on CVD diamonds; GIA DiamondCheck documentation).
CVD diamonds typically contain very little nitrogen, unlike HPHT diamonds, which often show nitrogen-related absorption. This characteristic means CVD diamonds more frequently grow as Type IIa diamonds, a rare diamond type in nature (less than 2% of natural diamonds are Type IIa, but most CVD diamonds are Type IIa). High-purity Type IIa natural diamonds are among the rarest and most valuable naturals; in lab-grown form, the same purity is achievable routinely.
CVD technology has driven the lab-grown diamond market's growth since approximately 2016–2018 because it scales more efficiently than HPHT for gem-quality production, produces larger stones more reliably, and is less capital-intensive to establish. Most of the lab-grown diamond cutting done in Surat today processes CVD rough.
The two manufacturing processes for gem-quality lab-grown diamonds. CVD now dominates commercial production because of better scalability for gem sizes. Source: GIA Gems & Gemology research on lab-grown diamonds; GIA DiamondCheck documentation.
Can you tell a lab-grown diamond from a natural one?
With the naked eye: no. With a 10× loupe: generally no, unless the lab-grown stone has specific inclusions characteristic of its growth process (metallic flux inclusions in some HPHT diamonds). With professional gemological instruments: yes, reliably, specific spectroscopic analysis (UV-Vis, photoluminescence spectroscopy), DiamondView imaging, and other tests can identify lab-grown origin with high reliability (GIA DiamondCheck documentation; GIA Gems & Gemology, various lab-grown identification articles).
This identification reliability is why GIA and IGI run every submitted stone through screening instruments before grading. A stone whose origin cannot be confirmed from screening is referred for detailed testing before a natural or lab-grown certificate is issued. The diamond grading industry's response to lab-grown technology has been to invest in detection, the identification reliability of professional laboratory instruments is now high enough that a lab-grown diamond cannot be passed as natural by any major grading laboratory.
Lab-grown diamond certification: IGI and GIA
Lab-grown diamonds are graded on the same 4Cs scale as natural diamonds, cut, colour, clarity, carat. IGI is the dominant certification laboratory for lab-grown diamonds globally and in India; the vast majority of lab-grown diamonds in the Indian market carry IGI certificates (IGI institutional information, igi.org; trade consensus documented in Rapaport Magazine and IDEX, 2022–2026).
GIA also grades lab-grown diamonds. On GIA lab-grown certificates, the report clearly states "Laboratory-Grown" in the report heading, and the girdle inscription includes "LG" notation. IGI's lab-grown certificates similarly state the laboratory-grown origin clearly. There is no ambiguity on a legitimate GIA or IGI certificate about whether a stone is natural or lab-grown (GIA Diamond Grading Report documentation, gia.edu; IGI report documentation, igi.org).
CIBJO's Laboratory-Grown Diamond Guidelines (2024) specify that lab-grown diamond certificates and product specifications must clearly state the manufacturing process (HPHT or CVD) in addition to the standard 4Cs grades. Not all currently available lab-grown certificates show this, verify that any significant lab-grown purchase has a certificate that clearly states both the origin (laboratory-grown) and the manufacturing process (GIA LGD Guidelines implementation; CIBJO LGD Guidelines, cibjo.org, 2024).
Legal names: what you are and are not allowed to call them
International standards and national consumer protection frameworks specify the permitted and prohibited names for lab-grown diamonds (ISO 18323:2015, iso.org; CIBJO Diamond Blue Book 2024, cibjo.org; FTC Jewelry Guides, ftc.gov, 2018):
Permitted terms: "Laboratory-grown diamond," "synthetic diamond," "laboratory-created diamond," "man-made diamond," "lab-created diamond," "lab diamond." All of these clearly communicate the non-natural origin.
Prohibited or problematic terms: "Cultured diamond", prohibited by CIBJO and problematic under ISO 18323 because it implies naturalness by false analogy with cultured pearls (which are genuine pearls from living organisms). "Real diamond" used as a contrast to mined diamond without separate clear disclosure of laboratory-grown status, potentially misleading. Simply "diamond" without the laboratory-grown qualifier, violates ISO 18323:2015 which requires the qualifier for synthetic diamonds.
Why this matters for Indian buyers: In India's unregulated marketing environment, lab-grown diamonds are sometimes marketed using terms that obscure their non-natural origin. A buyer who does not know to ask "is this natural or lab-grown?" may purchase a lab-grown diamond believing it is natural and pay natural diamond prices. Always ask explicitly and verify by checking the IGI or GIA certificate, which must clearly state laboratory-grown origin.
The key questions for any buyer deciding on lab-grown
Do you value the diamond's rarity? Natural diamonds are rare, geological accidents of extreme rarity and antiquity. Lab-grown diamonds are not rare, they can be produced in quantity by anyone with the manufacturing equipment. If rarity and the idea of owning something that took billions of years to form matters to you, this difference is real and meaningful. If you primarily value the stone's beauty and physical properties, rarity may be irrelevant.
What is your budget priority? Lab-grown diamonds of identical 4Cs grades to natural diamonds sell for approximately 70 to 85 percent less than natural equivalents in early 2026 (observed from IGI-certified lab-grown pricing vs GIA-certified natural pricing in Indian and international markets, 2026). A ₹3 lakh budget that buys a 0.70ct natural diamond (GIA Excellent, H, VS2) can buy a 2.50ct lab-grown diamond of similar 4Cs grades. If visible size per rupee is your priority, lab-grown offers dramatic value.
Are you concerned about investment value? Natural diamonds, particularly GIA-certified high-quality natural diamonds, have historically retained value reasonably well in the secondary market. Lab-grown diamonds do not hold value in the same way, prices have fallen approximately 60 to 80 percent since 2020 as production scaled, and there is no established secondary market for lab-grown goods at anything near purchase prices. If resale or investment value matters, natural diamonds have a clear advantage.
Do you have ethical concerns about mining? Lab-grown diamonds bypass all mining-related ethical concerns, no conflict diamond risk, no mining community impacts, no geological disruption. For buyers who prioritise ethical sourcing above all else, lab-grown provides complete certainty on this dimension. Natural diamonds can be sourced from ethical, well-governed mines, but this requires specific provenance documentation that is not universally available.
Primary sources cited here
GIA Gem Reference Guide (2006 edition). Gemological Institute of America, Carlsbad, California. [Diamond chemical composition, crystal structure, hardness (10 Mohs), refractive index (2.417), dispersion (0.044), natural formation conditions (depth 150–200km, temperature 900–1300°C, pressure 45–60 kbar).]
GIA Gems & Gemology research on laboratory-grown diamonds. Various issues. Gemological Institute of America. [CVD and HPHT growth processes; Type IIa characteristics of CVD diamonds; detection methods; trace element differences; metallic flux inclusions in HPHT.]
GIA DiamondCheck and screening documentation. gia.edu. Gemological Institute of America. [Natural vs synthetic screening process; spectroscopic identification methods; laboratory protocol for origin confirmation.]
ISO 18323:2015. "Jewellery, Consumer confidence in the diamond industry." International Organization for Standardization, Geneva. iso.org/standard/62163.html. [Permitted and prohibited descriptors for lab-grown diamonds; "diamond" without qualifier = natural; "laboratory-grown diamond" required terminology.]
CIBJO Laboratory-Grown Diamond Guidelines (2024). World Jewellery Confederation, cibjo.org. [LGD product specification requirements; HPHT/CVD process disclosure; "LG" prefix for clarity grades on grading documents.]
US Federal Trade Commission, Jewelry Guides (2018 revision). ftc.gov. [FTC removal of "natural" as required component of "diamond" definition; lab-grown disclosure requirements under US consumer protection.]
IGI institutional information. igi.org. International Gemological Institute. [IGI as dominant lab-grown certification laboratory; lab-grown certificate format with "Laboratory-Grown" notation and process disclosure.]
Frequently asked questions
Are lab-grown diamonds "fake" diamonds?
No. A lab-grown diamond is a real diamond, chemically and physically identical to a natural diamond. "Fake" would describe a simulant like cubic zirconia (CZ) or moissanite, materials that look like diamond but have completely different chemical compositions and physical properties. A lab-grown diamond is not a simulant. It is a genuine diamond that was grown in a laboratory rather than in the earth. The distinction that matters is between natural and synthetic origin, both are real diamonds; they have different origins.
Will a lab-grown diamond scratch or chip?
No more than a natural diamond will. Both are equally hard (10 on the Mohs scale) and equally brittle in terms of cleavage vulnerability. Lab-grown and natural diamonds behave identically under normal jewellery wearing conditions, they resist scratching from anything other than another diamond, and they are vulnerable to chipping or fracture if hit sharply at a cleavage direction. The wearability of lab-grown jewellery is identical to natural diamond jewellery.
How can I verify a diamond is lab-grown or natural when buying?
The most reliable method: the GIA or IGI certificate. A GIA lab-grown certificate says "Laboratory-Grown" in the report heading and has "LG" in the girdle inscription. An IGI lab-grown certificate similarly identifies the stone as laboratory-grown. Verify the certificate at gia.edu/report-check or igi.org and confirm the girdle inscription under a 10× loupe. Any diamond sold as natural without a GIA or IGI certificate that you can verify online should be treated with caution for purchases above ₹1 lakh.