How to Read a GIA Report

So, you may have just found your dream diamond, and it comes with a GIA  (Gemological Institute of America) report. But what exactly does that report mean? Understanding a GIA report is crucial for making an informed purchase. In this guide, we'll walk you through the key elements of a GIA report, helping you decode the information and make a confident decision.

Anueva Jewelry | 1.20CT Antique Old European Cut Natural Diamond

What Is a GIA Report?

A GIA Diamond Grading Report is a detailed assessment of a diamond's characteristics, which are evaluated by experts at the Gemological Institute of America. The report provides a comprehensive evaluation of a diamond's 4Cs: Color, Clarity, Cut, and Carat Weight. Additionally, it may feature a visual representation of the diamond's clarity attributes through a plotted diagram, as well as a graphical depiction of its proportions. This report is exclusively issued for loose natural diamonds weighing 0.15 carats or greater. For standard round brilliant cut diamonds falling within the D-to-Z color range, the report also includes an assessment of the GIA Cut grade. Essentially, this report serves as a buyer's blueprint for a loose diamond's overall quality. For a better understanding of the report, here's an example:

Demystifying the GIA Report

Let's dive in! The GIA report primarily focuses on what is commonly referred to as the 4Cs: Carat, Cut, Color, and Clarity. We'll go over them briefly, but if you'd like a more in-depth explanation of what these are, head over to this guide. For a quick refresher, here is a basic definition of the 4Cs:

CARAT: Carat refers to the weight (not size) of the diamond. One carat is equivalent to 200 milligrams. Larger diamonds are generally more valuable, but remember that carat weight is just one factor among many.

CUT: The cut of a diamond is about how well it has been shaped and faceted. It affects how the diamond interacts with light, influencing its sparkle and brilliance. The GIA grades cut on a scale from Excellent to Poor.

COLOR: Diamond color is graded from D (colorless) to Z (light yellow or brown). The less color a diamond has, the more valuable it tends to be

CLARITY: Clarity measures the presence of internal and external flaws, known as inclusions and blemishes. The grades range from Flawless (no inclusions or blemishes visible under 10x magnification) to Included (inclusions and/or blemishes visible to the naked eye).

Step-by-Step Guide

Now, let's walk through what each individual element is in the report. Follow along with the marked blue numbers to see what item we're talking about.

GRADING REPORT

1. DATE: The denotes the date that the diamond was examined by GIA.

2. REPORT NUMBER: Each report receives a unique GIA number that is registered in the GIA’s extensive global database. You can use this number to look up any report in the database.

3. SHAPE AND CUTTING STYLE: Here, the report defines the shape of the diamond. The outline of the diamond is the shape, and the pattern of the facet arrangement is the cutting style.

4. MEASUREMENTS: The diamond’s dimensions are listed in two different ways, depending on the stone shore. Round diamonds are listed as “minimum diameter by maximum diameter by depth. Fancy-shaped diamonds are listed as “length by width by depth.”

GRADING RESULTS

5. CARAT WEIGHT: This number denotes the weight of the diamond in carats. One carat is equal to 1/5 of a gram, and the number is recorded to the nearest hundredth of a carat.

6. COLOR GRADE: Here, you’ll find a letter ranging from D to Z. Diamonds are graded on the absence of color, ranging from colorless to light yellow or brown. If there is an asterisk next to the letters, this means that the diamond underwent a color treatment.

7. CLARITY GRADE: The relative absence of inclusions and blemishes. Graded on a scale from Flawless to Included based on size, nature, number, position, and relief of characteristics visible under 10x magnification.

8. CUT GRADE: The cut grade is not shown on this report, but keep an eye on other reports for this information. The cut grade assesses the face-up appearance, design, and craftsmanship of the cut diamond. They are graded on a scale from Excellent to Poor.

ADDITIONAL GRADING INFORMATION

9. POLISH: Ranging on a scale from Excellent to Poor, the smoothness of the diamond’s surface is marked here.

10. SYMMETRY: Ranging on a scale from Excellent to Poor, the precision of the diamond’s outline and the shape, placement, and alignment of its facets are marked here.

11. FLUORESCENCE: Here, the strength and color of the diamond, when viewed under long-wave ultraviolet light, is assessed and marked. If the report says “None” (such as in the example report), this means the range of fluorescence lies somewhere between Indiscernible to Very Faint. 

12. CLARITY CHARACTERISTICS: In this report, you can see that the next element is “Clarity Characteristics.” In other reports, this section is sometimes called out separately and includes both a plotted diagram and a symbol key. The plotted diagram is a representation of the shape and cut of the diamond and includes symbols that show where the type of clarity characteristic lies. The example report only notes which clarity characteristics were discovered in the assessed diamond, but here is a visual example what other reports may show:

13. INSCRIPTION: If the diamond includes any text, symbols, logos, or a unique GIA report number inscribed on the diamond’s girdle, it will be noted in this section of the report.

14. COMMENTS: This report does not include this element, but if any additional identifying characteristics are discovered and noteworthy, they will be included in the report here under a “Comments” section.

PROPORTIONS AND SCALES

15. PROPORTION DIAGRAM: Under the “Proportions” section, you’ll find a graphic profile representation of the diamond’s actual proportions.

16. GIA COLOR SCALE: Finally, on the right of the report, you may find some different scales. The first one on this report is the Color Scale, which shows the diamond’s color grade, relative to the GIA Diamond Color Grading System.

17. GIA CLARITY SCALE: Similar to the Color Scale, the Clarity Scale demonstrates the diamond’s Clarity grade, relative to the GIA Diamond Clarity Grading System.

18. GIA CUT SCALE: The last scale is the Cut Scale. While not shown in this report, many reports may include this. It shows the diamond’s cut grade, relative to the GIA Diamond Cut Grading System.

SECURITY AND VERIFICATION

19. QR CODE: If your report comes with a QR code, you can scan the barcode to pull up and verify the information included in the report on the GIA database.

20. SECURITY FEATURES: The final feature of a GIA report is the security feature. This is only valid on physical, official copies of the report and may include microprinting, security screens, watermarks, barcodes, holograms, and/or sheet numbering to safeguard the report's integrity and allow you to authenticate the document.

You're Ready to Purchase a Diamond!

When reading a GIA report, it's important to consider the 4Cs together. For instance, a smaller diamond with a higher cut grade may appear more brilliant than a larger diamond with a lower cut grade. But, most importantly, just remember that your personal preferences and budget should guide your decision. Understanding a GIA report may help empower you to make a choice that aligns with your priorities.

While deciphering a GIA report may seem complex at first, we tackled with ease! Now that you understand all the elements that may show up on a GIA report, you'll be equipped to evaluate diamonds like a pro. As always, if you're still unsure about anything or have further questions, our Anueva team is always happy to provide additional guidance. Happy diamond hunting!