Trusted Expertise in
Gemstone Certification
International gemological laboratory providing comprehensive analysis and certification for diamonds, colored gemstones, pearls, and jewelry.
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Setting the standard in independent gemstone certification since 2019
The Antwerp Laboratory for Gemstone Testing (ALGT) is an independent gemological laboratory headquartered in the heart of Antwerp — the world's diamond capital. Founded in 2019, ALGT has built a reputation for precision, integrity, and innovation.
Our laboratory employs advanced spectroscopic techniques combined with classical gemological methods to deliver accurate and reliable certification for dealers, auction houses, jewelers, and private clients worldwide.
In addition to Antwerp, we operate a fully-equipped facility in Shanghai, China, serving the vibrant Asian gemstone market.
Why Choose ALGT
Tradition meets cutting-edge technology
Our Equipment
State-of-the-art instruments powering our analysis
Renishaw inVia™ Confocal Micro-Raman Microscope
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LIBS — Laser Induced Breakdown Spectroscopy
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EDXRF QUANT'X Spectrometer
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FTIR — Fourier-Transform Infrared Spectroscopy
UV-VIS-NIR Spectroscopy
DiamondView™
DTC Melee Sorting Machine
J-SCREEN Diamond Screener
Our History
A journey of growth and dedication to excellence
Our Team
Internationally certified gemologists
Segers Marc
Co-founder of ALGT. Over 30 years of experience in gemology. FEEG diploma holder and recipient of the KIEA Gold Medal for diamond expertise from the King of Belgium.
Mingyue Yang
Co-founder of ALGT. Senior gemmologist with expertise in gemstone testing, laboratory operations, and gemmological research, including pearl-related publications.
Sun Sijie
Graduate Gemologist (GG) and ALGT founding-team member, currently overseeing the daily administrative operations of the Shanghai laboratory.
Our Services
Comprehensive gemological services for trade and private clients
Medium
Essential identification and grading in a compact format. Ideal for standard gemstones.
Large
Comprehensive report with detailed analysis. Industry standard for high-value colored gemstones.
Luxury
Enhanced presentation with additional photographic documentation and spectroscopic data.
Premium
The ultimate gemstone passport. Bespoke documentation for exceptional and auction-grade pieces.
Service Price List 2025
In Euro, Excl. 21% VAT
Natural Diamond Report (loose)
| Carat Weight | Fee (€) |
|---|---|
| ≤0.29 | 32 |
| 0.30-0.49 | 37 |
| 0.50-0.99 | 42 |
| 1.00 + | 45/ct |
Rough Diamond Identification Report
| Carat Weight | Fee (€) |
|---|---|
| ≤0.99 | 30 |
| 1.00 + | 30/ct |
| Yield Calculation ≤0.99 | 40 |
| Yield Calculation 1.00 + | 40/ct |
Laboratory-Grown Diamond Report (loose)
| Carat Weight | Fee (€) |
|---|---|
| Any weight | 25 |
* ALGT reserves the right to change these prices at any time. Discounts may be applicable for large volumes.
News & Library
Latest from ALGT and the gemological world
ResearchRecently a deep blue 0.71 carat sapphire (heated) was submitted to ALGT for origin report
Recently a deep blue 0.71 carat sapphire (heated) was submitted to ALGT for origin report. According to the chemical analysis and inclusion characteristics, we concluded that the…
EventsWe are very proud to become the first platinum sponser for F.E.E.G. Symposiums 2024 in Brussels.
We are very proud to become the first platinum sponser for F.E.E.G. Symposiums 2024 in Brussels. Federation for European Education in Gemmology – Symposiums 2024 – 2025 Below some…
ResearchThis amazing 3.03 cts and 3.15 cts demantoid pair originated from Russia was recently brought in ALGT for research.
This amazing 3.03 cts and 3.15 cts demantoid pair originated from Russia was recently brought in ALGT for research. Since Russian demantoid often occurs as small grains with no…
Contact Us
Get in touch with our team
Antwerp, Belgium
ALGT Gemstone Laboratory
Proud member of
International Colored Gemstone Association
China Inspection Body and Laboratory Mandatory Approval