Glossary of terms Jewelry ~ GIA Color and Clarity Scales for Diamonds

GIA Scales GIA Diamond D-Z Color Scale
Clarity Grading Scale Color Grading Scale

Colorless ... to ... Fancy Yellow

Why does the GIA color grading system start at D? Before GIA introduced the GIA D-Z Color Grading Scale, a variety of other symbols were loosely applied throughout the industry. Not only were A, B, and C used without clear definition, but some dealers, taking a cue from the poultry business perhaps, started grading their diamonds double A (AA).

COLOR

Diamonds are graded by the GIA (Gemological Institute of America) color grading scale. Here are the basic color groups:

colorless

near colorless

light yellow, grey or brown

fancy-(red, green, blue, orange, purple, pink, yellow, black and exotic colors like cognac, chartreuse, and others)

The regular GIA scale for grading color in diamonds begins with D and ends with Z. Think of the alphabet without the A B C. Here is the scale: (due to the differences in computers and browsers these colors are not exact).

D (icy white), E F (colorless), G H I (near colorless), J K L M N to Z (light to darker hints of yellow, brown, and gray). After Z they are graded as fancy colors. The Hope Diamond at the Smithsonian is an example of a fancy natural blue.

For more information about COLOR.

CLARITY

Diamonds which have very visible inclusions are what the trade calls commercial quality and are the lowest on the clarity scale which would be graded I₁, I₂ or at worst, I₃. The I stands for included. Many of the cluster diamond rings sold at "discount" stores will have this effect (under normal light). Many treated stones also begin at this grade.

The GIA scale starts with flawless (no visible inclusions or blemishes when viewed using 10x magnification by a trained eye) and ends with I₃ ( highly visible inclusions easy for the unaided eye to see). The subscript in clarity definitions (i.e., the 2 in VS₂) refers to the location of inclusions, not the quantity. The following is the GIA clarity scale:

In this scale we measure the degree of internal inclusions and external blemishes. Inclusions can be small and/or large, they can appear white and/or black; the more inclusions and the easier they are to detect determines the clarity grade. Blemishes, on the other hand, are external and are such things as scratches, nicks, abrasions and chips that may appear on the surface of the diamond.

For more information about CLARITY.

CUT

Whether you prefer a round, pear, emerald cut, marquise or heart shape, the shape of the diamond and make (proportion and finish) both are elements of the CUT. The better the diamond has been cut, the better the make, thus the more beautiful the diamond will appear. This cutting process is the human factor and there is a wide range of expertise in the world. Some of the diamond cutting centers in the world are New York, Antwerp, Africa, India.

The make of a diamond is the overall appearance. If the diamond is pleasing to the eye, the probabilities are it has very good angles, good facet junctions, and very nice finish or polish. To help you better understand make, look at the three following diagrams:

Light travels best, reflecting and refracting, in the third diagram. It has the best dimensions, angles, and finish so it exits through the top of the diamond as sparkle (brillance, scintillation, and dispersion). The other diamonds lose that sparkle through their undersides.

NOTE: The first two are not the quality of diamonds you would knowingly buy, are they? Well, well, that is why many jewelry stores use what are called diamond lights. They are of such high intensity and particular wavelength that the lack of diamond sparkle under ordinary light is overcome.

More details about CUT.

CARAT WEIGHT

It takes 100 points to equal 1 ct. (carat). Diamonds that are called 3/4 ct. can be between 73-78 points. All fractions have a range of points that they can be. A diamond's weight is measured to the third decimal place, a thousandth of a carat, and rounded off to the nearest hundredth. Of course, the larger the diamond, the rarer it is, and the more expensive per carat it will be.

For more information about CARAT WEIGHT

GIA – Creators of the International Diamond Grading System

An independent nonprofit organization with over 700 employees, the Gemological Institute of America is internationally renowned for its impartial service as the world's most trusted authority in the grading of diamonds, and the identification of gemstones and pearls.

In 1953, GIA created the International Diamond Grading System – on which the famous 4Cs are based. For decades, consumers and jewelry professionals around the world have used the (Cut, Color, Clarity, and Carat Weight) to assess the quality of a diamond. As a result, the GIA D – Z color scale and GIA's FL – I3 clarity scale are recognized by virtually every professional jeweler and diamond expert in the industry.

Every Diamond Buyer's Need for Reassurance

The scientists, researchers, graders, and instructors at GIA believe that the acquisition of a diamond is an extraordinary symbol of love. It also represents a major investment in time, energy and money. You need to feel confident in your buying decision – and in the integrity of what you've acquired.

For Peace of Mind – Ask for an Independent Expert Analysis

Be sure your diamond is accompanied by an impartial third-party grading report, such as those issued by the independent GIA Gem Trade Laboratory.

With grading reports such as the GIA Diamond Grading Report and the GIA Diamond Dossier® (for diamonds under 1 carat on the GIA D-Z Color Scale) you receive a trusted and impartial analysis of diamond quality and authenticity.