Understanding the Four C’s of Diamonds
Cut
A misconception in regarding diamond cut is that cut refers to diamond shape alone, (i.e. Round Brilliant, Marquise, Pear Radiant). In actuality it is the proportions that are of most concern when evaluating a diamond’s cut. Every diamond regardless of it’s shape gets brilliance and fire through the cutting process and placement of facets which should allow the maximum amount of light that enters through it’s top to be reflected and dispersed back again through it’s top to your eye. A diamond with correct proportions is pictured in diagram 1.
You will see that because the angles are correct the light that enters is properly dispersed and returned to the eye through the diamond’s top facets. When a stone is cut too shallow as it is in the second diagram it is referred to in the trade as a “fisheye” because of the ring that appears around the bezel of the diamond resembling an eye. With this effect light leaks out and is not returned to the eye leaving a lifeless stone. In the third diagram you will see the diamond has been cut too deep giving the effect that is referred to in the trade as a “nail head”. Again in this case, light is not properly dispersed and when you look at the stone face-up because of the deep cut, the diamond resembles the head of a nail in it’s appearance because it looks dark and black. Cut is such a crucial factor in diamonds because if the proportions are off the maximum beauty of the diamond cannot be realized.
Color
When color is referred to in a diamond the general rule of thumb is the less the better with the exception of what are known as “fancy” colored diamonds. Fancy colored diamonds are colors that occur in nature other than the white or colorless diamonds of which we usually see. The Gemological Institute of America (GIA) rates the body color in white diamonds in grades D (no color at all) through Z (light yellow). Once a color grade surpasses the Z grade it is then termed “Fancy” yellow and is considered to be rare and valuable. Diamonds come in many colors, some of the most common being yellow, brown and blue to the more rare pink, green and purple, and the most rare being red. These do occur naturally as well as being color enhanced by man.
The standard GIA body color-grading chart is illustrated below:
The chart shows diamonds in five color ranges from D-Z. The changes from one color grade to the next are very subtle and take a trained eye and years of experience to be able to discern the difference.
Clarity
The clarity of a diamond is determined by the following five factors: size, number, nature, position and relief of imperfections when the diamond is viewed under 10x magnification. It is important to remember that only 2% of the world’s diamonds are pure enough to earn the grade Flawless, and therefore are extremely rare and expensive. Most diamonds contain very small inclusions or identifying characteristics referred to at times as “birthmarks” as they occurred while the diamonds were forming in the earth. Below are examples of diamonds falling into each of the clarity grades in the clarity scale invented by GIA.
Carat Weight
A diamond’s weight is measured in carats. Each carat contains 100 points, so for example, a half of a carat equals 50 points, a quarter carat equals 25 points etc. As the carat weight of a diamond increases so does it’s value. The larger the diamond is the more rare it is and prices increase accordingly. Most importantly two diamonds of the same shape and size can range in price drastically when you factor in the other 3 C’s.