Precision &Excellencein Every Gem
India's premier gemological laboratory providing internationally recognised diamond grading, gemstone identification, and certification services.
Trusted DiamondGrading & Reports
Comprehensive 4C grading — Cut, Colour, Clarity, and Carat — delivered by certified gemologists with international standards.
Scientific GemstoneIdentification
State-of-the-art spectroscopic and microscopic analysis for accurate identification of all natural, synthetic, and treated gemstones.
Welcome to Gemological Institute of Testing Lab
National Gem Testing Laboratory
About NGTL
National Gem Testing Laboratory (NGTL) was established to provide reliable and professional testing services for gemstones and diamonds. We use modern technology and industry-standard testing methods to identify and evaluate precious stones.
NGTL continuously adopts new technologies and quality standards to meet the changing needs of the gems and diamond industry. Our laboratory is supported by qualified and experienced gemologists and diamond graders who provide accurate identification and grading services.
Read MoreWhy Choose NGTL
The Standard of Gemological Excellence
Our laboratory combines cutting-edge technology with decades of expertise to deliver results you can trust.
Advanced Lab Equipment
Our laboratory is equipped with state-of-the-art spectrometers, UV-Vis analysers, and high-resolution microscopes to ensure precision identification.
Certified Gemologists
Every report is prepared by GIA, FGA, or IGI certified gemologists with years of hands-on industry experience in diamond and gemstone grading.
Fast Turnaround Time
We understand the value of your time. Standard reports are delivered within 3–5 business days, with express options available for urgent requirements.
International Standards
NGTL certificates are recognised internationally, adhering to CIBJO, GIA, and ISO grading standards accepted across 15+ countries worldwide.
Our Products
What We Bring To You
Comprehensive testing and certification services for diamonds and precious gemstones.
Our Achievements
Numbers That Speak For Themselves
Testing Process
How Our Process Works
A simple, transparent three-step process from sample submission to receiving your certified report.
Sample Submission
Securely submit your gemstone or diamond to our laboratory. Walk-in, courier, and pre-scheduled appointments are all accepted.
Lab Analysis
Our certified gemologists conduct a thorough multi-instrument analysis using spectroscopy, microscopy, and UV testing protocols.
Certification Issued
Receive your internationally recognised NGTL certificate — available as a physical document and a secure digital copy.