What Criteria is used for Grading
Diamonds are graded for certification by laboratories using diamond grading criteria. Four of these grading
criteria are critical to understand when making a diamond purchase or investment.
The Four Cs
Known as the “Four C’s” these diamond grading criteria are used as follows:
- color grading,
- cut grading,
- clarity grading and
- carat grading.
Color is the result of the composition of a diamond and it does not change. When a jeweler is describing the
color of a diamond they are referring to the presence or absence of color in white diamonds. Because a diamond with
no color allows maximum light to pass through, colorless diamonds are preferred for their sparkle.
|Color grading is an important part of grading diamonds, which determines
the value of a diamond, with colorless diamonds being most valued.
(Image from Gemnation.com)
Cut refers to a diamonds reflective quality. Most diamonds are cut with 58 facets. The brilliance of diamonds is
heavily dependent on the cut. The different angles and the finish of a diamond determine its ability to reflect
light and cause its brilliance and fire. Remember that the cut of a diamond can have an impact on its durability as
well as its beauty.
Some cutting faults can make a diamond prone to breakage. A diamond that is cut too thin can also cause light to
leak out of the back and the diamond will lose some of the sparkle and appear not to shine. So, as you can see Cut
is probably the most important of the Four C’s.
During the formation process, inner flaws, or inclusions occur in most diamonds. The number and size of these
inclusions determine what is referred to as the clarity of a diamond. Diamonds that are clear create more
brilliance and therefore are rarer and highly priced. To be considered “flawless”, a diamond must have no surface
or internal imperfections visible upon being viewed by a skilled diamond grader using 10 power magnifications.
Perhaps the best known criteria used in grading diamonds is carat grading. Carat is the unit of weight by which
diamonds are measured. One carat is equal to 200 milligrams. A carat is divided into 100 segments called points.
150 points would equal one and a half carats.
When you go to the store to make that all important diamond purchase, do not be shy! Ask questions, get the
answers needed to make an informed purchase. Shopping for certified diamonds enables you to make an informed
selection. Knowing the “four C’s” allows you to comparison shop and purchase the best diamond at a fair price. But,
before making a diamond purchase, shop around and decide what shapes and styles really appeal to you.
Knowing what criteria is used for grading diamonds will help you enjoy your diamond for years to