How to Read Your Certified GIA Diamond Grading Report

How to Read your GIA certified diamond - GIA report analysis

What is a GIA diamond grading report?

A GIA diamond grading report gives specific information about your diamond. Understanding all of the information on your diamond certificate relating to your stone is important. The following details relate to our main image. Each section of your diamond grading report provides key information about details such as the diamond colour, clarity and carat weight.

2023 Update on GIA dossier reports.

Early this year, GIA introduced digital diamond dossiers.

“The digital GIA Diamond Dossier supports our consumer protection mission, meeting the needs of the gem and jewellery buying public we work to protect every day,”

GIA President and CEO Susan Jacques.

Replacement GIA certificate

Please refer to our main image for the numbered positions of each of the following diamond grading report features. 

1. Date

This was the date of examination when your diamond was assessed within the diamond grading laboratory.

2. Report Number

A unique number is assigned to your diamond. Registered with GIA and searchable on their online report check database.

3. Shape and Cutting Style

The outline shape of the diamond and the pattern of the facet arrangement are referred to as the cutting style. The name of the diamond shape might vary from the generic shape name provided by a retailer. E.g. Princess Cut is usually described on the GIA diamond grading report as ‘Square Modified Brilliant Cut.’

4. Measurements

The dimensions of your diamond. Listed as minimum diameter – maximum diameter x depth for round diamonds and length x width x depth for other fancy shapes of diamonds.

5. Carat Weight

Weight of your diamond in carats. One carat is the equivalent of 1/5 of a gram. Recorded to the nearest 100th of a carat.

6. Colour Grade

An indication of the whiteness of your diamond. The GIA colour scale is used universally as an expression of the level of whiteness of a diamond. Ranges from D (whitest) down to Z.

Master set of diamond colour grade samples D - M

A set of colour-matched sample stones used to demonstrate diamond whiteness grades

7. Clarity Grade

The relative absence of inclusions or blemishes. Graded on a clarity scale ranging from Flawless to Included in various sub-divisions. Diamonds are graded under 10x magnification. Our video below shows an example of a Flawless diamond—considered the very best clarity grade available.

8. Diamond Cut Grade

The cut grade of a diamond takes information from the appearance, design and craftsmanship, appreciating the stone’s proportions. A grade applied runs between Excellent to Poor. The cut grade can affect the price by as much as 40%.

9. Polish

The polish of a diamond is the smoothness of the diamond’s surface, assessed on a scale ranging from Excellent to Poor.

10. Symmetry

The exactness of the diamond’s outline, shape and placement and alignment of facets, again based on a scale running from Excellent to Poor.

11. Fluorescence

Some diamonds exhibit fluorescence under Ultraviolet light. A description of ‘none’ represents a range of fluorescence from indiscernible to very faint. Strong fluorescence can result in lower prices with a noticeable ‘bluff’ appearance in certain conditions. Buyers seldom realise how fluorescence relates to the value of their diamond when viewing a GIA diamond grading report.

12. Inscription

Microscopically applied text, symbols, logos or the unique diamond grading report number applied to the girdle of the diamond.

Loose diamond photographed with GIA inscription

13. Comments

Additional identifying characteristics or features may be noted here, along with any treatments that might be detected.

14 . Proportion Diagram

Graphic representation of the diamond’s proportions.

15. Plotted Diagram

Shows a visual representation of your diamond, with blemishes and clarity characteristics illustrated as symbols, explained in the key.

16. Key to Symbols

Lists the characteristics and symbols shown on the plotted diagram if present.

17. GIA Colour Scale

Shows the GIA colour scale and relative positions of each whiteness grade within the scale.

18. GIA Clarity Scale

Shows the GIA clarity scale and relative positions of each clarity grade within the scale.

19. GIA Cut Scale

Shows the GIA scale of diamond cut grades for round brilliant cut diamonds and the relative positions of each cut grade within the scale.

20. Security Features

Microprinting, security screens, watermarks, a two-dimensional barcode, a hologram and a sheet numbering safeguard report integrity and facilitate document authentication. Such strict security systems prevent fraud and tampering with GIA diamond grading reports.

21. QR Code

A two-dimensional barcode that, when scanned, verifies the data on the report against the GIA database of certified diamonds.

About Mark Johnson

My name is Mark and I'm founder at Serendipity Diamonds. By day you'll find me working in our showroom—in a variety of roles. My work (which I love) ranges from photographing jewellery, to writing blog posts and helping clients with my colleagues Drina, Emily and Debbie.

About Mark Johnson

My name is Mark and I'm founder at Serendipity Diamonds. By day you'll find me working in our showroom—in a variety of roles. My work (which I love) ranges from photographing jewellery, to writing blog posts and helping clients with my colleagues Drina, Emily and Debbie.