The 4 C's of The Diamond
After the mid-20th Century, the 4C’s of Diamond Quality envisaged by the GIA, Gemological Institute of America became the universal method for assessing the quality of any diamond, anywhere in the world. The creation of the Diamond 4Cs meant two very important things: diamond quality could be communicated in a universal language, and diamond customers could now know exactly what they were about to purchase. Here is how it works:
A Diamond Cut varies from a diamond to diamond and how cutters choose to shape, facet and polish the diamond. Experts consider cut to be the most important out of the 4Cs because the brilliance and fire of a diamond depend greatly on its cut. For example, an ideal cut diamond is a round, brilliant, or princess cut diamond that is cut to ideal proportions and angles and has excellent polish and symmetry. An ideal cut diamond reflects almost all the light that enters it and is among the rarest cuts.
The highest quality diamonds are colorless, while those of lower quality have noticeable color, which manifests as pale yellow in diamonds. The Gemological Institute of America (GIA) grades diamond color on a scale of D (colorless) to Z (light yellow or brown).
Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called inclusions, and surface defects, called blemishes. Diamonds with higher clarity grades are more valued, with the exceedingly rare "Flawless" graded diamond fetching the highest price. Minor inclusions or blemishes are useful, as they can be used as unique identifying marks analogous to fingerprints. Clarity Grades are from F (Flawless) to I3 (Included)