What Is a GIA Certificate or Grading Report?
A GIA certificate most commonly refers to a document containing information on the quality characteristics of a particular diamond. To grade a stone on these characteristics, trained gemologists at the GIA inspect and measure the diamond’s most important features.
The findings are then included in a grading report, which can be used to establish quickly the quality of the stone it describes.
How Does the GIA Certification Process Work?
In order to have your diamond certified by the GIA, you will need to send it to the Institute’s laboratory. To do so, it is recommended that you use a reliable courier service and have your stone insured beforehand.
After your diamond is received by the GIA, trained gemologists will examine the stone’s most important quality characteristics and assign a grade to each of them.
For example, a diamond’s clarity is graded by looking at the stone under 10x magnification to determine the number, visibility, and position of any detectable flaws that may be present in the diamond.
The proportions of your diamond will also be measured, and depending on how close they are to the so-called “ideal diamond proportions,” the stone’s cut will be assigned a quality grade, ranging from Excellent/Ideal to Poor.
(This is mostly true for round diamonds; most other diamond cuts do not have such precise proportion benchmarks.)
Your diamond’s proportions and cut grade are some of its most important features, as they determine how much light the stone will return to the eye of an observer and how brilliant the diamond will look.
Can You Get a Diamond Ring Graded by the GIA?
The GIA does not grade complete pieces of jewelry; it only issues reports for gemstones.
Therefore, you cannot have your diamond ring graded by the GIA.
You can, however, get the quality of the individual diamonds in your ring evaluated.
An important thing to remember is that the GIA only grades loose stones because the setting in which a mounted diamond is put hides part of it and makes it hard to determine the stone’s exact features.
What If Your Diamond Is Not Loose but Is Mounted in a Setting?
If you want a report issued for the diamond in your ring, you should have the stone removed from the setting by a local jeweler before sending the diamond to the GIA. We recommend that you do not attempt to remove the diamond yourself as you may damage the setting or the stone.
If you want to have the quality of the whole ring determined, consider having it appraised by a professional appraiser, who will evaluate not only the piece’s stones but also its metal parts.
Keep in mind that the GIA evaluates diamond quality but does not determine the value of stones in monetary terms.
Related: Click here to browse a selection of diamond rings.
What Information Does a GIA Grading Report Include?
General Identification Information
This information is usually at the top of the grading report and contains data about the shape and measurements of the diamond as well as its laser inscription number.
The laser inscription deserves more attention as it can help you indentify a particular diamond.
This inscription is a small engraving burned on the edge of the stone and serves as a unique ID that can help match a diamond to its report.
Not all diamonds have laser inscriptions, though.
Diamond Quality Grades
The major diamond quality grades evaluated in the report are the so-called 4 Cs: The four most important quality characteristics that determine the value of a diamond.
They are as follows:
Color
This characteristic indicates how colorless the stone is. The G.I.A. grades diamond color using letters from D (Colorless) to Z (Light Yellow).
In general, the less color in a diamond, the higher its color grade.
Clarity
Clarity refers to how clean the stone looks under 10x magnification. The fewer internal defects (inclusions) and external flaws a diamond has, and the less visible they are, the higher its clarity grade.
The G.I.A. evaluates clarity using grades starting from IF (Internally Flawless) all the way down to I (Included).
Cut
The cut grade in a diamond report refers to how close the stone’s proportions are to those of the so-called ideal cut, which maximizes the brilliance and sparkle of a round diamond.
The top grade a stone can get on this characteristic is Excellent, and the lowest one is Poor.
Carat
This is a number that indicates how much the diamond weighs and is measured in carats. (1 carat equals 200 milligrams, or 0.2 grams.)
In general, since bigger diamonds are rarer, they are disproportionately more valuable than smaller ones.
Additional Information
The information in this section gives more detail as to the features of the diamond.
Although not considered as critical as the 4 Cs, these data points provide more depth and can help you get a better understanding of the stone’s characteristics.
Polish
This characteristic refers to how smooth the stone’s polished surface is. The top grade for polish is Excellent, and the surface of well polished diamonds lets light enter them unobstructed, contributing to their enhanced brilliance.
Diamonds whose polish is graded Poor, on the other hand, have visible lines from the polishing process on their facets. These surface imperfections can reduce the amount of light that enters the stone and is reflected by it, resulting in diminished brilliance.
Symmetry
Diamond symmetry is a measure of how well aligned the facets of a stone are. The highest grade for this characteristic is Excellent.
Some of the imperfections that result in diminished symmetry are an off-center bottom or top of the stone, a wavy girdle (the edge of the stone), a stone’s top that is not parallel with the girdle, and irregularly shaped facets.
Most diamonds have some asymmetry, but it becomes clearly visible in stones with a Fair or Poor symmetry grade.
Fluorescence
The grade on this characteristic indicates whether a diamond fluoresces when lit with ultraviolet light. If the diamond does not exhibit such an effect, the report will list that the stone has no fluorescence.
If the stone fluoresces, the report will indicate how visible the fluorescence is (e.g., faint or strong).
Diamond Diagram
A G.I.A. report includes a diagram of the diamond (top, bottom, and side view) that shows the arrangement of the stone’s facets and the location of its visible inclusions.
You can use this figure as a map that indicates the most important “birthmarks” of the diamond.
The diagram also shows the proportions of key parts of the diamond (e.g., the diameter of the stone’s top as a percentage of the girdle). These values are important as they indicate how closely the stone’s proportions are to those considered ideal.
Two important features mapped on a diamond’s diagram are the stone’s culet and girdle.
Culet: You can see this diamond part indicated on the side-view diagram. The culet is the bottom facet of the stone.
A diamond can have no culet at all, and some people think that a missing culet makes the pointed bottom of the stone more likely to break. If a culet is present, the report will indicate how big it is.
The most preferable size for this bottom facet is small to medium; if the culet is too big, it becomes easily visible from the top of the stone.
Girdle: This is also a diamond part indicated on the profile diagram and refers to the edge of the stone. The diagram will show how big the girdle is and whether it is faceted.
If this part is too thin, it could break easily. If, on the other hand, the girdle is too thick, it will distort the proportions of the stone to some extent.
Why Should You Have Your Diamond Certified?
So what are the benefits of having your diamonds certified? Here are some of them:
Third-Party Certification
A certificate issued by a reputable, independent gem lab provides reliable information about the most important quality characteristics of a diamond.
In addition, the document also serves as an assurance that this assessment is not only unbiased but also reasonably precise, as certification authorities such as the GIA employ highly qualified gemologists, who have sophisticated equipment at their disposal.
Valuation
The information in a diamond’s certificate can help you to establish the stone’s value.
Although such a document issued by the GIA does not list how much a diamond is worth, the grades assigned to its color, clarity, and cut can be used to infer a reasonable value range based on how much similar diamonds sell for.
Identification
A GIA certificate can make the identification of your diamond easier.
Every grading report issued by the Institute bears a unique number that identifies the diamond described in the document, and you can elect to have this identifier inscribed on the girdle of your stone with laser.
If you ever need to verify that you have the right diamond, you can always check its microscopic laser inscription (if it has one) and see if it matches the number in the stone’s report.
Where to Buy Diamond Jewelry?
We recommend James Allen (read review) because you can see a 360-degree video for any diamond before buying it.
Blue Nile is another reputable diamond retailer we recommend.