To be sure that you receive the most value when purchasing diamonds, it is of paramount importance to learn as much as possible about how diamonds are classified so that you become familiar with the various aspects and topics associated with diamonds, namely the Four Cs: Cut, Color, Clarity, and Carat.

Cut

The first and most important of the Four Cs is Cut and what makes it a ‘prime cut’ with respect to its beauty!

Cut has two main references. The first is the SHAPE and the second is QUALITY. The shape is determined by the diamond cutter and thus a human factor is brought in, as well as the complicated skills required to cut the various shapes, all of which are unique to each diamond – no two diamonds are ever the same as they all come from separate rough stones. A well cut diamond shows light reflected from one facet to another, which then disperses through the top of the diamond. More than one diamond may be cut from a large rough stone, but the larger the stone, the greater the value, as has been noted at many diamond auctions!

The influence on the beauty of a diamond depends on its cut and thus the ‘sparkle’ or light performance that we expect from such a stone. The various types of cut or shape are different and each has unique characteristics: Round (also known as Brilliant), Princess, Cushion, Marquise, Emerald, Radiant, Pear, Oval, Asscher and Heart. The differences are defined by the number of facets and direction in which these facets are cut, creating unique optical appearances for each type of cut. The quality is determined by proportions, symmetry and polish. ‘Proportions’ of the various cuts determine whether or not the diamond is too shallow when the diamond loses brilliance, too deep.

When buying a diamond, select the highest grade within your budget. The choice of cut is a purely personal one as all cuts are beautiful; however, some cuts are a lot more costly than others due to the amount of extra care that has to taken in the cutting process, so this choice may be dependent on your budget.

Clarity

Diamonds are formed by heat and pressure exerted on crystallising carbon deep within the earth. This process causes various characteristics or imperfections to be found in almost every diamond. These internal inclusions are sometimes so tiny that they are not visible to the naked eye and do not affect the beauty of a diamond at all. They may appear as dark or white dots, scratches or cracks. External imperfections are known as blemishes and may also be caused during the mining process. Clarity is simply a measure of these imperfections and the effect they have on the overall appearance of the stone. No diamond is 100% pure but the lack of visible flaws in a ‘flawless’ diamond increases the value of the stone. Diamonds which have imperfections which cannot be seen by the naked eye still have very good value.

Clarity of diamonds is evaluated by a diamond grader who uses a 10-power magnification process. The clarity is then noted with respect to the kind of inclusions seen, their size, color and position within the stone. The grade then reflects the degrees of visibility. The clarity grade affects the price and is also an indication of the diamond’s vulnerability as heavy inclusions can cause diamonds to break.

Colour

Color in diamonds occurs due to traces of certain elements such as nitrogen, as well as the pressure involved in its crystalline formation in the earth. It is the second most important characteristic to consider when buying a diamond, it manifests as pale yellow and its grade is based on lack of color or its whiteness. Color is a personal choice but remember that the less color, the higher the grade. The human eye detects sparkle first, then color. The highest grade is D and the lowest is Z. Good dealers only sell diamonds with a grade higher than J.

The GIA (Gemological Institute of America) uses a 12-letter alphabetical grading scale of D to Z, with D having the least amount of color and therefore being of the highest grade. Those at the Z end of the scale show darker tones. If the color is more intense than a Z grading, then it becomes a ‘Fancy Color’ diamond. The value of ‘Fancy Color’ diamonds can be very high if the natural color is intense. These colors include bright yellow, champagne, pink, blue and green. Orange, purple and red diamonds are very rare and command high prices. The more intense the color, the rarer and more valuable is the diamond.

When a diamond is set, the color or lack of color will change according to the metals in which it is set. Examples are that of a colorless D grade diamond which is best seen in a platinum setting, a yellow diamond in yellow gold and a pink diamond in rose gold; however this is also a matter of personal preference.

Carat

Carat is always about weight and its impact on price! The weight may not reflect the size and to understand this you need to consider the weight together with the distance in mm across the top of the diamond as viewed in a set stone and the actual cut grade. A well cut diamond appears larger because of the light that is reflected out of the top. A badly cut diamond may seem smaller as much of the weight may be in the base and thus lacking reflected light. In essence a high cut grade with a low weight may appear larger than a poor cut grade with a large weight.

Price increases with weight as large diamonds are more rare than small ones and more desirable for purchasers; however, the factors of cut, clarity and color also come into play when considering price. If a piece of jewelry has more than one stone, then the combined weight is known as total carat weight or TW.