Delhi Gold TestingAGL Laboratory
Delhi's Trusted CVD & HPHT Detection Laboratory

CVD & Lab-Grown
Diamond Testing Laboratory

Using advanced photoluminescence spectroscopy, FTIR analysis, and high-power digital microscopy, our certified diamond testing laboratory in Delhi distinguishes natural diamonds from synthetic CVD/HPHT laboratory-grown diamonds and identifies simulants like Moissanite and Cubic Zirconia.

Verify Your DiamondView Diagnostic Methods
Macro view of a brilliant-cut diamond placed on a testing stage in a gemstone analysis laboratory being scanned by a spectrometer laser

Laboratory Diagnostic Suite

While lab-grown diamonds share an identical chemical blueprint with natural stones, their crystal lattices retain distinct growth markers. Simulants differ entirely at the molecular level. Our laboratory detects these microscopic variations.

biotech

CVD & HPHT Detection

We use Photoluminescence (PL) spectroscopy to detect silicon-vacancies (CVD) or metallic fluxes (HPHT), and DiamondView ultraviolet imaging to trace geometric growth patterns and phosphorescence.

PL Spectroscopy & UV Scan
electric_bolt

Moissanite Verification

Silicon Carbide conducts heat similarly to diamond. We isolate Moissanite by checking for double refraction (birefringence) under 10x-60x magnification and utilizing electrical conductivity.

Birefringence & Conductivity
scale

Cubic Zirconia (CZ)

A heavy zirconium dioxide simulant. We detect Cubic Zirconia through specific gravity measurements (CZ has ~1.6x the density of diamond) and thermal resistance testing.

Specific Gravity & Thermal Drift
light_mode

White Sapphire & Glass

Corundum and glass simulants lack diamond's high refractive index (RI 2.42) and dispersion. We identify them via refractometry (RI ~1.76 for Sapphire) and polariscope analysis.

Refractometry & Polarizing

Diamond & Simulant Verification Matrix

Technical properties compared to establish absolute diagnostic certainty during analysis at our Rohini laboratory.

Material TypeCompositionRefractive Index (RI)Thermal ConductivityKey Distinguishing Laboratory Test
Natural DiamondCarbon (C)2.42 (Singly Refractive)Exceptional (~2000 W/m·K)Natural nitrogen impurities (Type Ia/Ib), mineral inclusions, and irregular growth lines under magnification.
HPHT Synthetic DiamondCarbon (C)2.42 (Singly Refractive)Exceptional (~2000 W/m·K)Metal flux inclusions (Ni, Fe, Co), strong phosphorescence, and cuboctahedral growth patterns under DiamondView.
CVD Synthetic DiamondCarbon (C)2.42 (Singly Refractive)Exceptional (~2000 W/m·K)Silicon-vacancy (SiV-) defect line at 737nm detected by Photoluminescence, and tabular growth striations.
Moissanite (Mozinite)Silicon Carbide (SiC)2.65 - 2.69 (Doubly Refractive)High (~150 W/m·K)Birefringence (displays facet doubling under 10x loupe), electrical conductivity, and high dispersion (intense rainbow fire).
Cubic Zirconia (CZ)Zirconium Dioxide (ZrO₂)2.15 (Singly Refractive)Very Low (Thermal Insulator)High Specific Gravity (5.6 - 6.0, feels 1.6x heavier than diamond), immediate failure on standard thermal tester, lower hardness (8.5 Mohs).
White SapphireAluminum Oxide (Al₂O₃)1.76 - 1.77 (Doubly Refractive)LowMuch lower Refractive Index, lacks dispersion/fire (looks glassy), doubly refractive, and low thermal conductivity.
Professional gemologist inspecting a diamond certificate inside our AGL lab
The Ledger of Value

Why Diamond Certification Matters

verified_user

Investment Security

A laboratory-backed diamond report verifies identity and grades, protecting your capital value across all global diamond trading exchanges.

gavel

Laser-Inscribed Provenance

Tested diamonds receive a microscopic laser inscription on the girdle, linking the physical gemstone directly to its secure digital database registry.

history_edu

Ethical Tracing

We strictly audit the supply chain of all submissions, ensuring diamonds certified by our laboratory are conflict-free and compliant with the Kimberley Process.

Frequently Asked Questions

Find answers to the most common queries regarding CVD/HPHT lab-grown diamond testing, 4C grading reports, and verification procedures.

What is the difference between a natural diamond and a lab-grown CVD/HPHT diamond?

keyboard_arrow_down
Natural diamonds crystallize deep in the Earth's mantle over millions of years under extreme heat and pressure. CVD (Chemical Vapor Deposition) and HPHT (High Pressure High Temperature) diamonds are grown in laboratories. While chemically, physically, and optically identical to natural diamonds, they have distinct microscopic growth lines, flux residues, and carbon patterns that Delhi Gold Testing can identify.

How does Delhi Gold Testing distinguish natural diamonds from CVD or HPHT lab-grown diamonds?

keyboard_arrow_down
Our Rohini diamond testing laboratory uses advanced diagnostics, including Photoluminescence (PL) spectroscopy to identify silicon-vacancy defects in CVD stones, ultraviolet fluorescence scans, and polariscope examinations to view the stress patterns and birefringence lines unique to natural growth.

Can a standard handheld diamond tester detect CVD or HPHT synthetic diamonds?

keyboard_arrow_down
No, standard handheld diamond testers (which measure thermal or electrical conductivity) will identify CVD and HPHT synthetic diamonds as "diamonds" because their carbon chemistry is identical to natural stones. Only laboratory-grade spectroscopic tools (like those in our AGL center) can definitively separate natural and synthetic stones.

What is included in an AGL Diamond Grading Report?

keyboard_arrow_down
Our diamond reports include a detailed 4C assessment: Cut grade, Color grade, Clarity classification, and exact Carat weight. Additionally, reports feature a plot diagram of inclusion types (feather, crystal, pin-point), ultraviolet fluorescence reactions, dimensional measurements, and a clear declaration of origin (Natural or Lab-Grown).

Begin Your Laboratory Analysis

Secure your diamond's legacy with the industry's most rigorous scientific verification. Appraisals and testing bookings available at our key global stations and Delhi headquarters.

Book a Consultation