What is diamond certification?
A diamond certificate is a grading report from an independent gemological laboratory. It details the diamond's physical and optical properties, including cut, colour, clarity, and carat weight, along with further quality criteria such as polish, symmetry, and fluorescence. The certificate gives you a full, objective picture of what you're buying.
Gemological laboratories
Every diamond we sell is certified by the International Gemological Institute (IGI). We chose IGI for their thoroughness and their established expertise in lab-grown diamond grading. There are several well-known laboratories in the industry:
IGI (International Gemological Institute)
The largest independent gemological laboratory, with a well-established reputation for lab-grown diamond grading. IGI reports are detailed and widely recognised by jewellers worldwide.
GIA (Gemological Institute of America)
Known for strict, consistent grading standards. GIA has historically focused on mined diamonds but also grades lab-grown stones.
AGS (American Gem Society Laboratories)
Takes a scientific approach to grading, with a particular focus on cut quality and light performance.
HRD Antwerp
Based in the diamond capital of Europe, HRD Antwerp is a respected grading authority with long-standing industry recognition.
GCAL (Gem Certification & Assurance Lab)
Offers detailed grading with a strong emphasis on accuracy. GCAL certificates include light performance imagery alongside standard grades.
How to read a diamond certificate
A certificate can look technical at first glance. Here is what each section covers:
Certificate number
A unique identifier for the report. This number is laser-inscribed on the diamond's girdle, so the stone can always be matched back to its certificate.
Shape and cutting style
Describes the diamond's outline shape (round brilliant, oval, princess, and so on) and how it has been faceted.
4Cs grades
Individual grades for cut, colour, clarity, and carat weight. These are the core quality indicators most people compare when choosing a diamond.
Measurements
Exact dimensions and angles of the diamond.
Additional Grading Information
Includes polish, symmetry, fluorescence, and a clarity diagram showing internal characteristics.
The Importance of Certification
Unbiased Verification
Certification ensures the diamond's qualities are assessed by an independent expert.
Value Assurance
Helps you compare quality characteristics and pricing on a like-for-like basis.
Resale and Insurance
A certificate is commonly requested for insurance and can support resale discussions.
Verifying Your Diamond Certificate
You can verify the authenticity of your diamond's certificate by entering its number on the certifiers website:
Our Commitment to Quality
At Diamond Labs, we focus on transparency. We exclusively supply diamonds certified by the International Gemological Institute (IGI), so each stone includes independent grading details you can verify.