Diamond Grading

Various characteristics of diamonds are graded and categorized by the diamond industry. Learning about diamonds is first learning about the “four Cs” of diamonds which are considered the most important grades and categories:

  • Cut
  • Clarity
  • Color
  • Carat weight

These are the criteria jewelers use when grading diamonds, and they’re the ones you’ll need to understand to buy the right diamond for you.

R & D Jewelers uses the Dia View diamond viewing system. See what our expert jewelers see by viewing the diamond at 200 times the actual size.

The 5th C: Confidence
A good jeweler is your first step in designing custom jewelry or any diamond purchase. R & D Jewelers is knowledgeable about diamonds and can help you feel comfortable in making your important purchase.

Cut

First, don’t confuse diamond “cut” with “shape.” Shape refers to the general outward appearance of the diamond, (such as round, emerald, or pear). When a diamond jeweler (or a diamond certificate) says “cut,” that’s a reference to the diamond’s reflective qualities, not the shape (or at least it should be, we have found that even some “jewelers” don’t appear to know the difference between “cut” and “shape”).

The quality of the “cut” does make a difference in how a diamond looks.
Diamond cut is perhaps the most important of the four Cs, so it is important to understand how this quality affects the properties and values of a diamond. A good cut gives a diamond its brilliance, which is that brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determine its ability to handle light, which leads to brilliance.

Clarity

When we speak of a diamond’s clarity, we are referring to the presence of identifying characteristics on (blemishes) and within (inclusions) the stone.
If you think about the incredible amount of pressure it takes to create a diamond and the fact that natural diamonds are not grown in a sterile laboratory, it’s no surprise that most diamonds have flaws.
Basically there are two types of flaws: inclusions and blemishes. Inclusions refer to internal flaws and blemishes refer to surface flaws. However, in the diamond grades listed below, you’ll note that none of the grades include the term “blemish” — for the purposes of grading diamonds, all flaws are called “inclusions.”

Inclusions include flaws such as air bubbles, cracks, and non-diamond minerals found in the diamond. Blemishes include scratches, pits, and chips. Some blemishes occur during the cutting processes (most often at the girdle). Diamonds with no or few inclusions and blemishes are more highly valued than those with less clarity because they are rarer.

Color

When jewelers speak of a diamond’s color, they are usually referring to the presence or absence of color in white diamonds. Color is a result of the composition of the diamond, and it never changes over time.
Because a colorless diamond, like a clear window, allows more light to pass through it than a colored diamond, colorless diamonds emit more sparkle and fire. The formation process of a diamond ensures that only a few, rare diamonds are truly colorless. Thus the whiter a diamond’s color, the greater its value.

Diamonds graded G through I show virtually no color that is visible to the untrained eye.

[NOTE: Fancy color diamonds do not follow this rule. These diamonds, which are very rare and very expensive, can be any color from blue to green to bright yellow. They are actually more valuable for their color.]
To grade ‘whiteness’ or colorlessness, most jewelers refer to GIA’s professional color scale that begins with the highest rating of D for colorless, and travels down the alphabet to grade stones with traces of very faint or light yellowish or brownish color. The color scale continues all the way to Z.

The latest in technology including the Dia View diamond viewing system and the colorimeter diamond color grading system can be found at R & D. This equipment helps them in design and repair.

Carat Weight

A carat is a unit of measurement, it’s the unit used to weigh a diamond. One carat is equal to 200 milligrams, or 0.2 grams.
Size does matter. It is not, however, a measure of your love.
Keep in mind that differences in size are clearly visible… even to the untrained eye.

The word “carat” is taken from the carob seeds that people once used in ancient times to balance scales. So uniform in shape and weight are these little seeds that even today’s sophisticated instruments cannot detect more than three one-thousandths of a difference between them.

[NOTE: Don’t confuse “carat weight” with “karat,” the method of determining the purity of gold.]
The process that forms a diamond happens only in very rare circumstances, and typically the natural materials required are found only in small amounts. That means that larger diamonds are uncovered less often than smaller ones. Thus, large diamonds are rare and have a greater value per carat. For that reason, the price of a diamond rises exponentionaly to its size.