Two diamonds of the same size may appear identical to the naked eye. However, each jewel could have a very different in value upon closer examination. There are four key quality characteristics to consider when grading diamonds: cut, clarity, color, and carat weight. Known as the “4 Cs” of diamond quality, these features represent the globally accepted standard for describing cut diamonds. The four Cs make it possible to express diamond quality in a universal language, allowing buyers all over the world to rely on the same evaluation.
The cut describes the shape of a diamond produced by grinding. A good cut enhances the brightness of a diamond and allows its fire to glow in the colors of the rainbow. Unlike other features covered by the four Cs, this attribute is determined by the talents of the grinder and not by nature. In order to achieve optimal reflection of incident light within the jewel, the diamond must have perfect proportions and be neatly ground. If it is too deep, some of the brightness is lost. If it is too shallow, light disappears through the pavilion. A large number of cuts exist to cater to individual taste. According to the diamond grading system, the brilliant cut is the most popular and sophisticated. A perfect brilliant reflects the light inside the diamond from one facet to another, allowing it to shine from the inside.
Clarity is one of the most important characteristics in diamond grading. Diamonds are natural products, which means they bear the fingerprints of Mother Nature. Almost all jewels contain inclusions, revealing something about how they were formed. In most cases, internal flaws are tiny carbon particles or microscopic cracks that typically cannot be seen with the naked eye. However, such minor aesthetic flaws impede the reflection of light inside the diamond to some extent, thus limiting its brightness. According to the four Cs diamond grading system, this reduces the value of the jewel because greater clarity means higher quality. So-called “flawless” diamonds are considered to be perfectly clear if no flaws can be seen even at ten times magnification – such stones are therefore extremely rare and incredibly valuable.
The color of a diamond is of great importance when classifying diamonds using the four Cs system. People may think of these jewels as colorless, but a flawless white light is extremely rare and very precious. Instead, cut diamonds usually have a slightly yellow tint, visible only upon close inspection by a diamond grading specialist. When it comes to classifying their quality, diamonds are placed on a scale from D (top quality) to Z (significant coloration). As diamonds progress from a yellowish tint to brownish tint, their value diamond decreases – unless they radiate an intense, pure color: only so-called “fancy diamonds” can match the preciousness of a white diamond. These sparkle in strong shades of yellow, red, blue, or pink – and their scarcity makes them exceeding popular. Only one in about 100,000 diamonds is a fancy diamond.
The carat describes the weight of a gemstone in the four Cs classification system. One carat (1 ct) corresponds to 0.2 g, and this unit is divided into 100 points. For example, a 50-point diamond weighs 0.5 ct or 0.1 g. The carat does not reveal much about the size of a jewel, though, because the proportions and cut make all the difference. In rings, necklaces, and earrings, the pavilion is hidden in the mounting. The apparent size of the stone is determined by giving the crown – the visible part of the diamond – the best possible cut. Two jewels with the same carat weight can thus appear to be different in size and be worth very different amounts. Only if the other features included in the grading system indicate high quality can the carat weight of a diamond increase its value.