How to Check the Purity & Authenticity of Lab-Grown Diamonds

Your lab-grown diamond is a real diamond. Fact check: Absolutely true. But how to prove it? Here’s how. 

Lab-grown diamonds are chemically, physically, and optically identical to natural diamonds, making them a sustainable and cost-effective choice. However, verifying their purity (quality factors like clarity and cut) and authenticity (confirming they are lab-created diamonds, not simulants or misrepresented natural stones) requires robust methods. Home tests can identify diamonds versus fakes, such as cubic zirconia, but distinguishing between lab-grown and natural diamonds requires professional expertise. Below are effective methods to ensure your lab-grown diamond is genuine and of high quality, backed by gemological standards. 

However, it’s crucial to know that purity and authenticity are two separate paradigms for evaluating diamonds. 

Understanding Purity vs. Authenticity in Lab-Grown Diamonds

Before diving into verification methods, it’s essential to clarify the distinction between purity and authenticity in the context of lab-grown diamonds, as these terms address different aspects of a diamond’s quality and identity.

• Authenticity: This confirms that the stone is a genuine diamond (created in a lab via HPHT or CVD processes) and not a simulant like moissanite, cubic zirconia (CZ), or glass. Authenticity also ensures that the diamond is accurately represented as lab-grown, rather than a natural diamond, thereby preventing misrepresentation. Verification involves checking for diamond-specific properties (e.g., carbon composition) and lab-grown origin through advanced testing and certifications.
• Purity refers to the diamond’s quality, primarily its clarity (the presence or absence of inclusions and blemishes), as well as other factors such as color and cut. Lab-grown diamonds often have fewer inclusions due to controlled production, but their purity varies. A grading report from a reputable lab details these characteristics, ensuring the stone meets quality standards.

Certifications from trusted labs, such as GIA or IGI, cover both authenticity (verifying the diamond’s lab-grown origin) and purity (assessing clarity, color, cut, and carat weight, or overall quality). Understanding this distinction helps you prioritize the correct verification methods. 

 With this distinction clear, let’s explore foolproof methods to ensure your lab-grown diamond is genuine and of high quality, backed by gemological standards.

1. Secure a Grading Certificate from Accredited Labs

A grading certificate from a reputable gemological laboratory is the cornerstone of verifying a lab-grown diamond’s authenticity and purity. These reports detail the stone’s characteristics and confirm its lab-grown origin, preventing misrepresentation.

• Gemological Institute of America (GIA): 

The global benchmark for diamond grading, GIA, is trusted worldwide. As of October 1, 2025, GIA has transitioned from the traditional 4Cs (cut, color, clarity, and carat) for lab-grown diamonds to simplified “Premium” and “Standard” tiers based on overall quality. Diamonds below a minimum threshold may not receive a report. GIA utilizes advanced spectroscopy and incorporates laser inscriptions for enhanced traceability, ensuring authenticity. Submit uncertified diamonds to GIA for testing.

• International Gemological Institute (IGI):

The IGI retains the complete 4Cs grading system for lab-grown diamonds, assessing carat weight, color, clarity (noting the minimal inclusions typical in lab-grown stones), and cut (evaluating brilliance). Their Light Performance Analysis scientifically measures sparkle, including brightness, fire, and contrast. IGI’s certificates, bolstered by expanded facilities like their new Surat center, are trusted in Asia and Europe.

HRD Antwerp, while respected in Europe, has ceased offering lab-grown diamond certification, leaving the GIA and IGI as the primary options. Always demand a certificate—it’s your proof of quality and origin. Without one, have the diamond tested at a lab to confirm its value.

2. Consult a Certified Gemologist for Visual and Microscopic Inspection

A professional gemologist provides hands-on analysis beyond consumer capabilities, identifying subtle signs of lab-grown origin and assessing purity.

• Inclusions and Growth Patterns: Lab-grown diamonds may exhibit metallic inclusions (resulting from HPHT processes) or strain patterns under magnification, unlike natural diamonds, which often display feathering or pinpoint flaws. Check for laser inscriptions, such as “Laboratory-Grown” or a serial number, on the girdle using a 10x jeweler’s loupe, a standard feature in certified stones.
• Professional Analysis: Gemologists utilize high-magnification microscopes to identify growth patterns specific to lab-grown diamonds. While not definitive on its own, this complements certification for robust verification. Seek gemologists affiliated with bodies like the American Gem Society for reliable appraisals.

3. Utilize Advanced Laboratory Testing Methods

Advanced tools, typically available at gem labs or specialized jewelers, provide definitive proof of a diamond’s lab-grown status and quality.

• UV Fluorescence and DiamondView Testing: Lab-grown diamonds may exhibit distinct fluorescence patterns (e.g., intense glow or CVD striations) under UV light, unlike natural diamonds. GIA’s DiamondView uses short-wave UV to reveal these patterns, confirming origin with high accuracy.

• Spectroscopy Techniques: Raman spectroscopy analyzes molecular structure, while Fourier-Transform Infrared (FTIR) spectroscopy detects impurities, such as nitrogen, which is often absent in lab-grown diamonds. These non-destructive tests verify composition and origin.
• GIA iD100 Device: This portable spectrometer quickly distinguishes lab-grown diamonds from natural ones and simulants by analyzing optical properties, offering professional-grade certainty.

4. Leverage Cutting-Edge Traceability Technologies

For ultimate confidence, opt for diamonds with embedded traceability features.

• Opsydia Nano-IDs: This UK technology etches submicron codes beneath the diamond’s surface, linking to a chain-of-custody database. These tamper-proof nano-IDs verify lab-grown origin and are nearly impossible to remove without recutting the stone, ideal for high-value diamonds.
• Other Innovations: Technologies like Alrosa’s nano-marking provide similar tracking. Ask jewelers if your diamond includes such features, especially for smaller melee stones.

5. Industry Shifts: Changing Standards, Changing Game

Recent changes in grading practices reflect the evolving lab-grown diamond market, impacting how authenticity and purity are assessed.

• GIA’s New Approach: As reported by India Today, GIA has phased out the 4Cs for lab-grown diamonds, adopting “Premium” or “Standard” labels starting October 2025. Stones that do not meet quality thresholds may go ungraded. This simplifies certification but reduces detail, emphasizing lab-grown diamonds as products of technology rather than geological rarity.
• IGI’s Commitment to Detail: IGI continues to use the 4Cs for both lab-grown and natural diamonds, adding Light Performance Analysis to quantify sparkle (brightness, fire, and contrast). Their expansion, which includes a new certification facility in Surat’s Hira Bourse, enhances accessibility and trust, according to The Times of India and Rapaport.
• HRD Antwerp’s Exit: According to The Times of India, HRD Antwerp has ceased certifying lab-grown diamonds, thereby narrowing options for European buyers.

What to Avoid: Home Tests Are Not Reliable for Origin

Home methods like thermal conductivity probes, fog tests, or basic diamond testers only confirm if a stone is a diamond—not whether it’s lab-grown or natural. Electrical conductivity tests may suggest differences but require expert interpretation. These are inadequate for authenticity; instead, rely on lab certification and professional tools.

Quickfact Cheatsheet

Frequently Asked Questions 

Q: How can I tell if my lab-grown diamond is real?

A: The most reliable way is to obtain a grading certificate from a trusted lab like GIA or IGI, which confirms the diamond’s lab-grown origin and quality. Advanced tests, such as spectroscopy or UV fluorescence, conducted by professionals, can also verify authenticity.

Q: Do lab-grown diamonds come with the 4 Cs certification?

Yes, but changes are here. IGI still grades LGDs using the 4 Cs, while GIA now uses “Premium” or “Standard” labels. HRD Antwerp has exited LGD grading altogether.

Q: Can I test the authenticity of a lab-grown diamond at home?

At-home tests, such as fog, UV glow, or water drop checks, are fun indicators, but only a lab can confirm authenticity with specialized equipment.

Q: Which certification is most widely recognized in Europe or Asia?

• Europe: IGI and HRD are respected.
• Asia: IGI has gained significant recognition, particularly with its expansion in Surat.
• Global: GIA remains the most universally recognized institution for gemstone grading.

Q: Do lab-grown diamonds hold value in the resale market?

Resale values are lower than naturals since LGDs aren’t rare. However, certified diamonds (IGI or GIA) tend to perform better in resale across the Indian, European, and US markets.

Q: What’s the difference between purity and authenticity in lab-grown diamonds?

• Authenticity: Confirms it’s a diamond (not moissanite or CZ).
• Purity: Refers to clarity and inclusions. Certifications cover both.

Q: Are diamond testers reliable to distinguish lab-grown from natural diamonds?

A: No, home testers like thermal or electrical conductivity probes can only confirm if a stone is a diamond, not its origin. They may be fooled by simulants like moissanite. Professional lab testing is required for accurate identification.

Q: What is the difference between GIA and IGI for lab-grown diamond certification?

A: GIA uses simplified “Premium” or “Standard” labels for lab-grown diamonds (as of October 2025), while IGI retains the detailed 4Cs grading and adds Light Performance Analysis for sparkle. IGI offers more detail, while GIA prioritizes simplicity.

Q: Are lab-grown diamonds less valuable than natural diamonds?

A: Lab-grown diamonds are typically less expensive due to their controlled production, but they hold value for their ethical and sustainable qualities. Their worth depends on quality factors such as cut, clarity, and carat, as certified by reputable laboratories.

Q: Where can I buy certified lab-grown diamond jewelry?

A: Trusted platforms like The Luxury Closet offer authenticated lab-grown diamond jewelry with GIA or IGI certifications. Their expert-verified collection ensures quality and authenticity, providing confidence in your purchase.

Q: What are nano-IDs in lab-grown diamonds?

A: Nano-IDs, like those from Opsydia, are microscopic codes etched beneath the diamond’s surface, linking to a database that verifies its lab-grown origin and history. They’re tamper-proof and ideal for traceability.

Q: Why did HRD Antwerp stop certifying lab-grown diamonds?

A: HRD Antwerp exited lab-grown diamond certification to focus on natural diamonds, as reported by The Times of India. This leaves GIA and IGI as the primary labs for lab-grown certification.

Q: Is it safe to buy lab-grown diamond jewellery online?

Yes, buying lab-grown diamond jewellery online is safe when you shop with trusted platforms. Always ensure that your piece comes with certification from reputable agencies such as GIA, IGI, or HRD, and verify that the laser inscription on the girdle matches the details on the certificate. At The Luxury Closet, every lab-grown diamond undergoes strict authentication and quality checks before listing, so you can shop with confidence. With secure payment gateways, insured shipping, and a transparent return policy, your diamond purchase is both safe and stress-free.

In a nutshell…

Ensuring the purity and authenticity of lab-grown diamonds requires professional certification, expert inspection, and advanced testing. Start with a GIA or IGI grading report, consult a certified gemologist, and consider traceability technologies like Opsydia’s nano-IDs. Industry shifts, like GIA’s simplified labels and IGI’s detailed approach, offer options based on your preference for simplicity or specificity. Avoid home tests—they can’t confirm origin. Purchase from reputable platforms like The Luxury Closet to secure certified, high-quality lab-grown diamond jewelry that shines brilliantly.

Shop with Confidence at The Luxury Closet

For those seeking authentic lab-grown diamond jewelry, The Luxury Closet is a trusted platform offering a curated selection of high-quality pieces, called The Diamond Edit. Based in Dubai, our premier online marketplace specializes in pre-owned and new luxury items, ensuring that GIA-verified certifications accompany every lab-grown diamond. Their rigorous authentication process, backed by in-house experts, guarantees you’re investing in genuine, ethically sourced jewelry. Whether you’re eyeing a sparkling lab-grown diamond ring or a pair of elegant earrings, The Luxury Closet provides competitive pricing in AED and a seamless shopping experience, making it the ideal destination for sustainable luxury. Visit The Luxury Closet to explore their collection and purchase with confidence.

Sources:

limelightdiamonds[dot]com/

indiatoday[dot]in/india-today-insight/story/lab-grown-diamonds-set-to-lose-4cs-certification-will-buyers-really-bother-2736195-2025-06-05 

timesofindia.indiatimes[dot]com/city/surat/igi-expands-lgd-certification-amid-industry-shifts/articleshow/123004302.cms?utm_source=chatgpt.com