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Evaluating a Diamond for its Quality

4C's of a Diamond

Diamond is a stunningly beautiful precious stone and before evaluating a diamond for its quality, you must educate yourself with the 4 C's, which are four important characteristics of diamonds, which defines the gem stone and its overall value and worth. The 4 C's for defining a diamond are cut, clarity, color, and carats.


One of the most important factors in evaluating a diamond for its quality is the cut of a diamond. A diamond with a perfect cut will be brilliant and reflects light in a stunning fashion. The cut of a diamond actually refers to how many well-proportioned facets are in the stone.

The cut also refers to diamond's shape, such as pear, emerald, oval, or round. The angles and shapes of a diamond are important to a diamond's optical quality and the overall sparkle of the diamond. Too deep or shallow cut diamonds will have dull and lifeless appearance.


Is the diamond you are examining dull and cloudy or clear? Clarity of a Diamond refers to how clear the stone actually is. If it has inclusions, flaws or imperfections, then it will not be worth as much as another diamond with relatively few flaws. Jewelers rate clarity using the following chart prepared by the Gemological Institute of America (GIA):

  * I1, I2, and I3- These diamonds have imperfections or flaws which can be seen with the naked eye.

  * SI1, SI2, SI3- These diamonds have small inclusions.

  * VS1, VS2 -These diamonds have very small inclusions.

  * VVS1, VVS2- These diamonds have very, very small inclusions.

  * Internally Flawless-These diamonds may have very minor blemishes on the outside of the stone.

  * Flawless-These diamonds do not have any inclusions and are considered to be perfect and is very expensive and rare.


Perfect Ideal diamonds are considered to be transparent or colorless. Perfectly clear Colorless diamonds are the most expensive and rarest of diamonds. Colors of a diamond are rated with an alphabet grading system of the Gemological Institute of America (GIA) that starts with "D" and ends with "Z". Diamonds which are completely colorless fall in the "D" and "E" grade while colored, fancy diamonds are at the other end of the alphabet, at "Y" and "Z."

Jewelers mainly use two main ways to judge a diamond based on color. A set of reference stones are used sometimes and find the closest match between the diamond and the reference stone to determine its color grade. Alternatively, some jeweler uses a colorimeter, which electronically measures the color of the stone and determines its grade within 1/3 of a grade.

Carat / Weight

Diamond Carat is the term used to describe the weight of a diamond. 1 Carat= 200 milligrams. A diamond with a high amount of carat weight is usually more expensive than multiple smaller diamonds of equivalent amount of carats. Finding the larger diamonds is rarer of an occurrence that's why diamonds of larger carat weight are always expensive. Evaluating a diamond quality by the amount of carats is difficult since diamonds with different shape and different levels of clarity will be priced differently even if they have the same amount of carats.