A Guide to Diamond Grading Reports
What you should know about diamond grading reports
Grading Reports are meant to provide clarity, and yet consumers often get so focused on the data they forget about the most important aspect of the diamond or gem: it’s beauty and the feelings it inspires. Here are answers to the most common consumer questions when it comes to diamond and gem grading reports.
While a diamond grading report can help explain the quality factors like color, clarity, cut and carat weight, it should not be a primary factor when shopping for a diamond. Our diamond expert can help you understand their unique characteristics and determine the best diamond for your budget.
Grading Report or Certificate or Appraisal?
Let’s start with what a diamond grading report is not: It is not a jewellery appraisal or a certificate of the stone’s value. Key differences:
- A jewellery appraisal is typically used for insurance purposes and any after-purchase care or design follow up. It should not be used as a substitute for a grading report.
- A Certificate guarantees the exact grade or value of the stone, while a grading report is a subjective report and offers a grade within a range of values.
Consider a grading report a blueprint of a diamond’s properties that verifies diamond authenticity and quality. As you search for your perfect diamond, a grading report can help explain the quality factors of the stone based on scientific properties, but it is still subjective in that it is the opinion of the individuals who graded the diamond and is based on the lab’s grading standards. This is why there are sometimes minor discrepancies between grading reports from different labs.
What is Included with a Grading Report?
A diamond grading report describes in detail the characteristics of an unmounted diamond. How that information is referenced the varies depending on the lab, but most grading reports contain:
- The 4Cs of diamond quality: color, clarity, cut and carat weight. This will differ slightly for colored gemstone grading reports, where color is the most valued quality factor. The grades on the report represent a range of each “C”
- The stone’s characteristics: shape, proportions, finish
- Any known treatments if applicable
- Many grading reports also include a diagram of inclusions that can affect how light is displayed in a diamond. When considering diamond inclusions, keep in mind that truly flawless diamonds are extremely rare, representing less than 1% of all finished diamonds.
Who Publishes the Grading Report?
Diamond and gemstone grading reports are provided by laboratories within the jewellery industry. Here are some of respected labs that offer diamond and gemstone grading reports or certificates:
Gemological Institute of America (GIA)
International Gemological Institute
Gem Certification & Assurance Lab (GCAL)
American Gem Society (AGS)
GS Laboratories Inc.