The diamond grading system does not tell the whole story. Today’s over reliance on the diamond certificate can lead to false perceptions of value. In order to be practical, GIA certificates can only describe a diamond’s characteristics (cut, colour, clarity, carat weight, as well as symmetry and polish) as discrete values that fit into a grading scale; this is an inherent limitation of a diamond certificate. In reality, an infinite number of gradations are possible. While useful to establish baseline standards, you can’t show beauty with letters and numbers. In a comparison, one will be distinctly more pleasing to the eye than others.
Compare diamonds side by side whenever possible. Online shopping may be the norm nowadays, but refrain from buying any gemstone sight unseen!
Cut, which refers to the proportions, symmetry, and polish of a diamond, is a measure of how its facets interact with light. Cut is the only characteristic that is directly influenced by man and the one with greatest influence on a stone’s beauty. It’s what we perceive as sparkle when a well proportioned diamond maximizes the amount of light that reflects out of the top. It should not be confused with the shape of a stone.
Cut (as per GIA grading)
Symmetry – refers to how precisely the facets of a stone align and intersect. It can include off centre and misshapen facets
Polish – refers to how smooth the facets have been polished and if any surface marks are visible from the polishing process.
For fancy shape stones (those other than round), there are wild variations in cut. This is why cut grades are not assigned to these shapes. Comparing several such stones together before making a decision is strongly recommended.
For a white diamond, the less color, the higher the grade. Even the slightest hint can make a dramatic difference in value.
Subtle changes in color can be detected by gemologists in side by side comparisons. To an untrained eye, color becomes even harder to spot once a stone is set, especially if jewelry made of a warm metal like yellow or rose gold is chosen. In such a case, a perfectly cut diamond of H to L color can be considered. Not only will it still show beautifully, you’ll also save money!
The majority of diamonds contain small internal and surface imperfections called inclusions and blemishes. Clarity is the relative absence of these microscopic imperfections which can take the form of tiny white or black crystals.
What does this mean? Select a diamond at a point furthest down the clarity scale where you can no longer see an inclusion with the naked eye. If you can’t see them, why not save some money? It does not materially impact a diamond’s beauty unless you plan on walking around with a loupe.
Carat Weight (ct)
The carat is a unit of weight for gemstones; it’s not to be confused with size which is measured in millimeters. In general, the larger the diamond, the rarer it is, and since stones are sold by carat weight, the more expensive it becomes. However, weight alone does not determine the price. Other variables come into play as well. Two diamonds of equal carat weight can have very different costs based on the other 3 C’s. A smaller stone may be more beautiful than a larger, heavier one with inferior cut, color and clarity.
If you’re on a budget, prioritize on cut, color, clarity and buy short weight. That is, choose a diamond a bit under well known markers like 0.50 ct, 1.00 ct,, 1.50 ct, 2.00 ct, etc…
Diamond Size or Weight?
When a diamond is cut from a rough stone, the diamond cutter is faced with a choice to maximize for the best cut or to preserve weight. More often than not the cutter delivers what the customer or market demands, weight, making more profit on his initial investment by sacrificing beauty. The result is a less than well proportioned stone.
The lighter, well cut diamond shown in the diagram will command a higher price per carat not only because of its superior beauty, but also because it’s more expensive to create.
The heavier, deep cut diamond may sell for more in total, earning the diamond cutter more profit, but for the consumer, it’s at the expense of beauty.
This means that if you buy the deep cut 1.50 ct diamond in this example, you’re not getting the great deal or brilliance you thought. Moreover, the deep cut stone will look small next to a well cut 1.50 ct diamond.