Diamond Grading Criteria
Do You Know 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
The Four Cs of diamonds
Known as the “Four
C’s” these diamond grading criteria are used as
- 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
which determines the value of a diamond, with colorless
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
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
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 come!