Diamond Color, Clarity, Cut and Carat Weight are collectively termed the 4Cs – the factors that, when combined,
define a diamond’s quality and ultimately determine its value. GIA created the 4Cs of Diamond Quality, which has
become the universal method for assessing the quality of any diamond, anywhere in the world. The creation of
the 4Cs means that diamond quality can be communicated in a universal language so diamond purchasers know
exactly what they are buying.
GIA’s diamond color grading system measures the absence of color, starting with D as colorless and continuing
to Z representing light yellow or brown. The distinctions between color grades are so subtle that they are often
invisible to the untrained eye but can make a big difference in diamond quality and price.
A diamond’s cut determines its sparkle. To fashion a stone with proportions, symmetry and polish worthy of an
excellent cut grade requires artistry and workmanship. The finer the cut quality, the more sparkle the diamond
Natural diamonds form from carbon exposed to tremendous heat and pressure deep in the earth. Diamonds
often contain clarity characteristics, called inclusions or blemishes. Inclusions are enclosed within the gem and
blemishes are on the surface of the diamond. If all else is equal, the closer a diamond is to flawless, with no
inclusions or blemishes, the higher its value.
Diamond weight is measured in carats. One carat is equal to 0.2 gram, about as heavy as a paperclip. Since larger
diamonds are more rare, they will cost more than a smaller gem with the same color, clarity and cut grades.