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 has.
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.
GIA Grading Report
The GIA Diamond Grading Report includes an assessment of a diamond’s 4Cs – Color, Clarity, Cut and Carat Weight – along with a plotted diagram of its clarity characteristics and a graphic representation of the diamond’s proportions. The GIA Diamond Dossier® includes these without the graphical representation of the clarity characteristics. The GIA laboratory issues diamond grading reports for loose, natural diamonds in the D-to-Z color range that weigh 0.15 carats or more.
Why ask for a grading report?
A diamond grading report is the scientific blueprint of a stone’s quality characteristics. A GIA Diamond Grading report is your assurance that your diamond is a natural diamond, with disclosure of any treatment to enhance color or clarity. The report provides the clear evidence that is vital to a confident purchase. A GIA Diamond Grading Report not only provides expert analysis of Color, Cut, Clarity and Carat Weight, it also contains a plotting diagram that clearly shows a diamond’s inclusions and clarity characteristics. The GIA Diamond Dossier® includes these without the graphical representation of the clarity characteristics. All GIA reports contain security features to prevent them from being forged or duplicated. GIA does not buy or sell diamonds, making an independent diamond grading report from GIA an unbiased assessment of the diamond
Established in 1931, GIA protects the public through gemological research, education, impartial gem identification and grading services, and instrument development. The world’s foremost authority in gemology, GIA sets the global standard for determining the quality of diamonds and performs research based identification of colored gems and pearls. GIA created the 4Cs of diamond quality and the International Diamond Grading System™, providing all who buy or sell gemstones with a common language for describing diamond quality. As an independent nonprofit organization, all of GIA’s activities are governed by its mission to serve the public. Visit GIA.edu