Diamond Certification Explained

A diamond certificate -- also known as a grading report or diamond dossier -- is an official document issued by an independent gemological laboratory that provides a comprehensive, objective assessment of a diamond’s quality characteristics. Think of it as your diamond’s identity document: a permanent, third-party record of exactly what you are buying.

The certification process begins when a diamond is submitted to the laboratory by a manufacturer, dealer, or jeweller. The stone is examined by multiple trained gemologists using standardised methodology, calibrated equipment, and controlled lighting conditions. Each gemologist grades the diamond independently, and their assessments are reconciled to produce a final grade for each quality characteristic. This multi-grader approach minimises subjectivity and ensures consistency.

The resulting certificate includes detailed information about the diamond’s 4Cs (Cut, Colour, Clarity, and Carat Weight), as well as its physical measurements, proportions, polish and symmetry grades, fluorescence, and any notable characteristics. For lab-grown diamonds, the certificate also specifies the growth method (CVD or HPHT) and may include additional details about the stone’s origin.

It is important to understand that a certificate is a quality report, not an appraisal or valuation. It tells you what the diamond is, not what it is worth in monetary terms. However, because it provides the objective quality data needed for pricing, it is the foundation upon which fair market value is determined.

The International Gemological Institute (IGI) was founded in 1975 in Antwerp, Belgium -- the historical heart of the global diamond trade. Over nearly five decades, IGI has grown into one of the world’s largest and most respected gemological laboratories, with operations spanning across multiple continents. It is widely recognised as the leading authority for lab-grown diamond certification.

IGI’s pre-eminence in lab-grown diamond grading is not accidental. When the lab-grown diamond market began to mature, IGI invested heavily in the science, equipment, and expertise required to accurately identify and grade these stones. Today, IGI has graded more lab-grown diamonds than any other laboratory in the world. Their experience translates to consistency, accuracy, and industry trust.

IGI grading is conducted under rigorous, standardised conditions. Diamonds are evaluated in a controlled environment with calibrated lighting (D65 daylight equivalent), and each stone is examined by a minimum of three gemologists. The laboratory uses advanced spectroscopic equipment to verify the diamond’s natural or lab-grown origin, and this determination is included on the certificate. IGI also employs proprietary software for measuring proportions and light performance, adding a technological layer to human expertise.

At Aurela Diamonds, we chose IGI as our exclusive certification partner because of their leadership in lab-grown diamond grading, their rigorous standards, and the trust they command throughout the industry. Every diamond in our collection comes with a full IGI grading report.

A diamond certificate can look dense and technical at first glance, but each section serves a specific purpose. Here is a breakdown of every major element you will find on an IGI grading report, explained in plain language.

The two most widely recognised diamond grading laboratories in the world are IGI (International Gemological Institute) and GIA (Gemological Institute of America). Both are independent, non-profit organisations with rigorous grading standards. The question of “which is better” is not straightforward -- it depends on the type of diamond you are purchasing.

For lab-grown diamonds, IGI is the clear choice. Their deep experience with lab-grown stones, investment in identification technology, and industry-leading volume of lab-grown certifications make them the most trusted authority in this category. For mined diamonds, both IGI and GIA are excellent, with GIA having a slight edge in historical reputation for natural stones. Regardless of the laboratory, what matters most is that you buy a certified diamond from a reputable grading body -- never an uncertified stone.

One of the significant benefits of certified diamonds is the ability to independently verify their grading report online. This provides an additional layer of trust and allows you to confirm that the physical diamond you received matches its documentation. Here is how to verify your IGI-certified diamond step by step.

If the certificate number cannot be found in the IGI database, or if any details on the digital report do not match your physical certificate, contact the jeweller immediately. At Aurela Diamonds, every diamond we sell has been verified against the IGI database before delivery, and we encourage all customers to perform their own independent verification for complete peace of mind.

The laser inscription on the diamond’s girdle can also be verified independently. Any jeweller or gemologist with a 10x loupe or a gemological microscope can locate and read the inscription. This physical-digital link ensures that the certificate belongs to your specific diamond and has not been transferred or falsified.

Buying an uncertified diamond is one of the most significant financial risks a consumer can take in the jewellery market. Without independent certification, there is no objective way to verify the quality claims a seller makes. A diamond that a seller describes as “G colour, VS1 clarity” could actually be J colour, SI2 clarity -- a difference that represents thousands of dollars in value but is extremely difficult for a non-expert to detect.

At Aurela Diamonds, certification is non-negotiable. We would never sell an uncertified diamond, and we believe no consumer should buy one. Explore our collection of ready-made rings, each accompanied by full IGI certification, or learn more about diamond quality in our Education centre and Sustainability page.