Learning about diamonds doesn’t have to be confusing and complicated. We can help by explaining the fundamentals of diamond grading: cut, color, clarity, and carat weight.
These criteria are used by the Gemological Institute of America (GIA), the world’s most reputable name in diamond evaluation and certification. Even though many diamonds of a similar grade can present differently, the overall grading system works well to classify diamonds and make diamond buying decisions easier.
Diamond Color Chart
The color of a diamond varies according to the number of trace elements contained within it as well as the dynamics of the light that passes through it. The combination of these two variables can result in diamonds with pink, blue, or yellow hues. Generally speaking, white diamonds follow a GIA grading system that runs from D (less colored) to Z (more colored). Among these, D-graded white diamonds are considered the most valuable.
This color designation is for white diamonds only. Diamonds that are intentionally sold as blue, yellow, or pink diamonds follow a different color grading scale entirely.
Diamond Cut Chart
The cut of a diamond refers to three key aspects: proportion, symmetry, and polish. When a diamond cutter is working with a raw diamond, a decision is made to either maximize the size of the final diamond or focus on creating a more proportional and symmetrical gem. While a higher price might be paid for the larger diamond, the better-proportioned one will yield more value per-carat.
When viewed in white light, a well-cut diamond should have an even ratio of dark-to-light sections. The ideal diamond cut will send light throughout the gem in an even pattern, highlighting every angle and bezel with just the right amount of emphasis on each.
The GIA uses a diamond cut grading scale that ranges from poor to excellent.
Diamond Clarity Chart
Because of how diamonds naturally form, there will almost always be imperfections that exist both within the diamond (inclusions) and on the diamond surface (blemishes). The clarity grading of a diamond tells us how few of these imperfections exist, with fewer being better.
The GIA clarity spectrum runs along 11 points, from flawless – meaning the diamond has no identifiable imperfections at 10x magnification, to L3 – meaning the diamond has multiple, pronounced inclusions and/or blemishes.
Carat Weight Chart
The unit of measure for conveying the weight of a diamond is in carat, abbreviated as ct. The word comes from the Carob Seed, which was used as a weight standard among early diamond traders. The larger the mass of a diamond, the higher its carat weight will be.
Smaller diamonds are exceedingly more abundant than larger ones. As such, the value of a diamond increases with its carat weight. Where a single-carat diamond might carry a value of $5,000, that same diamond might command a $50,000 price at a 3-carat weight.