In this blog, we'll explore key methods to differentiate between lab-grown and natural diamonds.

Let's Begin!

As the popularity of lab-grown diamonds increases, the question of distinguishing between the two has also grown. Since lab-grown diamonds have the same physical, chemical, and optical components as mined ones, differentiating between them can be quite complicated. While some methods are easier, such as looking for inscriptions, others require complex gemological examinations. 

Prabir, an expert in the diamond industry, has carefully outlined key points in this blog to help you effectively differentiate between lab-grown and natural diamonds. This article will take you through significant techniques that can help you determine whether a diamond is lab-grown or natural.

Check the Diamond Girdle Inscription

One of the most straightforward methods of telling apart a natural and lab-grown diamond is to look at the girdle inscription. Most lab-grown diamonds are laser-inscribed with markings that reflect their origin. Such inscriptions typically contain terms “lab-grown”, “LG”, or “CVD”, which stand for “Chemical Vapor Deposition”. These inscriptions are usually found on the diamond girdle, which is the thin ring that encircles the diamond and separates the crown from the pavilion.

Microscopic inscriptions are a practical first step in identification, as they can be viewed under magnification. However, some sellers with bad intentions may try to erase or change these specific markings, so further methods need to be created for greater accuracy.

Furthermore, while most top-tier gemology laboratories put distinguishing marks on lab-grown diamonds, other lower-quality diamonds may not have inscriptions for proper identification; hence, other tests become important.

Perform Expert Tests

Aside from inscriptions, testing is one of the best ways to differentiate natural diamonds from synthetic diamonds on a professional level. Sophisticated techniques in gemology can discover minute differences between the growth features, certain trace elements, and the patterns of fluorescence. These identification methods focus on the growth structure of diamonds and include the most common expert tests, such as spectroscopy, fluorescence analysis, and growth structure examination.

• Spectroscopy Test: With regard to the spectroscopic analysis, absorption exhibits patterns that are distinct between natural diamonds and synthetic diamonds. This test can detect trace elements such as nitrogen, which is usually present in natural diamonds but is rarely found in lab-grown ones.

• Fluorescence Under UV: It is also possible that diamonds will show fluorescence under UV light in a specific pattern. A number of lab-grown diamonds show greater fluorescent features than natural diamonds, but this alone will not suffice as a tell-tale sign.

• Investigation of Growth Characteristics: Natural diamonds grow over millions of years under great pressure and temperatures, resulting in specific features of growth visible through magnification. In comparison, lab diamonds that were created using the HPHT or CVD methods have dissimilar growth features like striations or metallic flux inclusions in the HPHT diamonds.

These characteristics can only be accurately interpreted by trained gemologists with special equipment. This is precisely the reason why expert testing will always be important when purchasing or authenticating valuable diamonds.

Examine the Report of Diamond Grading

A diamond's grading report is helpful in identifying whether the diamond in question is natural or lab grown. Lab’s of high repute such as GIA or IGI issue reports mentioning if the diamond is natural or lab grown for verification purposes.

The details in question greatly impact the value of the diamond, such as its cut, color, clarity, and weight. Both natural diamonds and lab grown diamonds are graded differently and the reports state “laboratory created stone” as a description, if applicable.

Because grading reports come from independent organizations, buyers have accurate information. Make sure to ask for the grading report when purchasing a diamond and use the laboratory's online database to verify it. Although it requires extra effort, this step can save a lot of money, starting a high-value diamond purchase.

Also read: How are Lab Grown Diamonds Made?

The Price Difference Between Diamonds

Lab-grown diamonds have a much lower price than natural diamonds, and this is also what distinguishes the two. Lab-grown diamonds are cheaper due to lower production costs and lower demand. The difference in pricing is helpful when determining the source of the diamond.

The price gap exists because the ease with which lab diamonds are produced in a controlled setting is in stark contrast with the extraction of naturally cultivated diamonds, which require extensive mining as well as the passage of millions of years. While lab diamonds enable affordability and sustainability, natural diamonds sustain the long-term investment value and retain rarity.

You may also like: Different Types of Diamond Cuts- A Complete Guide

Differentiating Lab-Grown Diamond from Natural Diamond

Aspect / Property	Natural Diamonds	Lab-Grown Diamonds (CVD / HPHT)
Origin	Formed deep within the Earth’s mantle over 1–3+ billion years under high pressure and temperature.	Grown in a controlled laboratory using HPHT (High Pressure High Temperature) or CVD (Chemical Vapour Deposition) over a few weeks.
Chemical Composition	Pure carbon (C) with trace elements like nitrogen or boron.	Pure carbon (C) with similar possible trace elements.
Crystal Structure	Cubic (face-centred cubic / diamond cubic).	Cubic (face-centred cubic / diamond cubic) – same as natural.
Hardness (Mohs Scale)	10 (benchmark for hardness).	10 – same as natural; equally resistant to scratching.
Specific Gravity (Density)	~3.52 g/cm³	~3.52 g/cm³ (practically identical, tiny variations possible).
Refractive Index (RI)	~2.42	~2.42 (same RI, so same basic sparkle potential).
Dispersion (Fire)	~0.044 (high dispersion, strong “fire”).	~0.044 – same fire and light dispersion.
Optical Appearance	Brilliance, fire and scintillation based on cut quality; may show natural growth zoning and inclusions.	Brilliance, fire and scintillation depend on cut; may show lab-typical growth patterns (e.g., graining in HPHT or layered structure in CVD). Visually, often indistinguishable to the naked eye.
Inclusions	Natural mineral inclusions, feathers, clouds, crystals, etc.	Metallic flux inclusions (HPHT), pinpoint clouds, or growth-related features; different inclusion “fingerprint” under magnification.
Fluorescence	Can fluoresce under UV (common: blue, sometimes yellow or other colors).	Can also fluoresce; pattern and intensity can differ slightly from natural, but not always.
Thermal Conductivity	Very high (basis of standard diamond testers).	Very high – standard thermal diamond testers usually read both as “diamond.”
Detection in Lab	Shows natural growth patterns and spectral features under advanced instruments (e.g., PL, UV-Vis-NIR, FTIR).	Shows lab-grown growth structures (strain patterns, growth sectors, etc.) and spectral features that can be identified using professional gemological equipment.
Environmental / Mining Impact	Requires mining (open-pit or underground), involving land disturbance and larger environmental footprint if not carefully managed.	No traditional mining; made in factories. Still uses energy (and depends on how “green” the power source is), but avoids large-scale earth excavation.
Certification	Certified by labs like GIA, IGI, SGL, HRD, etc., with “Natural Diamond” designation.	Certified by the same or similar labs, but clearly marked as “Laboratory-grown,” “CVD,” or “HPHT.”
Pricing (General Trend)	Higher per carat	Significantly more affordable for equivalent size, colour, and clarity.
Ethical Perception	Modern supply generally follows conflict-free protocols (e.g., Kimberley Process), but some consumers remain concerned about mining.	Often marketed as more ethical or “conflict-free” due to lab origin and no traditional mining, which appeals to many younger, conscious buyers.

The process of distinguishing between natural and synthetic diamonds requires a fusion of both basic and sophisticated methods. Employing tools to check for inscriptions, capturing expert gemological tests, and reviewing grading reports are all helpful to establish the diamond's origin. Furthermore, the difference in price will give some insight since lab diamonds are significantly less expensive than real diamonds.

Explore Ayanika's exquisite collection of meticulously crafted lab-grown diamond solitaire earrings, tennis bracelets, and more. 

For most consumers, purchasing natural versus synthetic diamonds is a matter of choice. Though there are ethical questions surrounding lab diamonds, natural ones are expensive because of their rareness and history. Either way, it is vital to obtain proper validation including legal proofs and certificates from professional examiners to make a successful purchase.