Buying a diamond has become, in some ways, even more confusing than it used to be. With such a deluge of information available on the internet, the average, non-gemologist consumer is now privy to such specific details as crown angle degrees, girdle measurements, pavilion depth and cut grade. While these and numerous other 'specs' are important to determine the brilliance and desirability of a well-proportioned diamond, the information can be confusing and is often even misleading. When first-time clients come to my showroom, I aim to educate them on the fundamentals of diamonds. Tried and true, nothing beats the personal experience of seeing loose diamonds shown side-by-side.

When you view several diamonds firsthand, you witness the visual nuances subjectively as your eyes adjust and allow you to see past the almost blinding glare. Then, as you begin to discern certain differences (which vary with the shape of the diamond), like color, shallower or deeper crowns, and smaller or larger tables, the characteristics begin to take on a life of their own. As a matter of fact, in the trade we often refer to diamonds as "lively" or "having a lot of life." After picking up some of the more obvious distinctions, you can actually begin to see variations in brilliance. Diamonds have an extremely high refractive index and this is what the refined diamond cutter manages to hone in on. Ultimately, the diamond cutter’s decisions are based on a three-way balance between saving weight (maximum yield), creating traditional proportions and having a sophisticated knowledge of the material which enables the cutter to bring out the scintillation of the diamond.

Luckily, I happen to have a diamond cutting factory on the premises (my showroom actually looks directly into it), so I’m able to give my clients a quick education before we get started on the design process. For those of you playing along at home, I offer this crash course in understanding diamonds. You may have heard of the "Four C's" used to describe a diamond (carat, color, clarity and cut). Even if you are familiar with their meanings, I think it is important to gain an understanding beyond the immediately apparent characteristics that each 'C' represents.

The first ‘C’ stands for the carat weight of the diamond. This is a universal measure of weight used for all gemstones. Carat weight is generally measured on an electronic scale and rounded to the nearest hundredth of a carat. The word ‘carat,’ by the way, is derived from the word carob. Carob seeds weigh within five hundredths of a carat. Because of the natural consistency of the carob seeds, they were used to determine the weight of diamonds traded in the markets of antiquity.

The second ‘C’ refers to the color of the diamond. The color is rated with a letter code, ranging from the colorless D, E or F colors down to the letter Z, which displays a light yellow or brown tint. What most people refer to as ‘whiter’ diamonds are actually more transparent stones which, like higher clarity diamonds, are rare. This is why crystal clear D through F colors are more desirable than mid- and lower- range colors. However, as you go beyond the color scale to the fancy color spectrum, the more saturated colors can actually surpass the colorless diamonds in terms of rarity and value. This is especially true with vibrant, unusual and exotic colors like red, orange, blue, green, pink, purple, and yellow. The fancy color diamonds are rated independent of the D-Z scale, using categories like “fancy light,” “deep,” “intense” and “vivid.”

A common misconception is that color has an effect on brilliance. Brilliance is the result of a well-cut diamond and is not affected by the color of the material. Furthermore, within each assigned color grading (letters D-Z) there is a small range of color variance. Colors are determined by comparing diamonds against a master set of diamonds in every color category. The stones are compared in a controlled lighting environment, where they are first analyzed from the sides to determine 'body color,' which has less glare to confuse the eye, and then from the top or 'face' view.

The third 'C' refers to the clarity of the diamond. This category ranges from Flawless (FL) to Imperfect 3 (I3). Imperfections, or inclusions, within the diamond and surface blemishes are graded in terms of concentration, length, location, reflection, and naked eye visibility. And within every category, they can be quite different. Imperfections are the result of natural air pockets, fractures and fissures that occurred as the diamonds were formed tens of millions of years ago. Hot and turbulent, high pressure conditions were prevalent in the earth’s crust as the continental plates were shifting and underground volcanoes were erupting. Sometimes other materials, like rust or mineral deposits like corundum (ruby and sapphire), can be found within these phenomenal crystals. The clarity of a diamond also has little if any effect on the brilliance of the stone unless it is very included (I2-I3) and is therefore cloudy or speckled with carbon and other visible “problem areas.”

Finally, the fourth 'C' relates to the cut of the diamond. While some people refer to the shape of the diamond as the cut, it generally indicates how well the material is cut. Ideally, the focus of the diamond cutter is to produce the most beautiful, brilliant and scintillating stone while generating the largest diamond possible from the rough material (maximum yield). Sort of like, if I'm only 5' 5" tall, what's the best body I can make for myself in the gym? Multiple factors, including the natural characteristics of the rough stone, the preferences of the owner of the rough diamond and the skill level of the cutter, will determine the quality of the cut. It is therefore really critical that you see a few loose diamonds side-by-side so that you can recognize the nuances in each stone’s “cut.”

I would like to add that when you are on the quest for your perfect diamond, I highly recommend the diamond have certification by a well reputed gem lab. The most popular and internationally accepted lab is the Gemological Institute of America (GIA). They are objective and require a consensus of three gemologists on every stone they grade. As with anything else, please bear in mind that human beings are running all the fancy instruments and then additional people are responsible for the actual printing of the reports. Hence there is a slight possibility that a clerical error can occur. I've seen it a few times and the GIA is very conscientious about making any necessary corrections. When there is a discrepancy and they admit that there was an oversight, there is no charge for the corrected "cert." But, in order to dissuade people from constantly submitting stones because they don't like the results on the report, the GIA will charge for re-submissions that yield no change.

I hope you found this overview helpful, and if you’d like the full side-by-side ‘bling-to-bling’ comparison, feel free to visit my showroom!

Israel Bien is a fine jewelry designer and diamond expert with Eternal Fine Jewels, Inc., located in the heart of New York City’s diamond district. Israel specializes in custom-designed engagement and wedding rings, as well as fine diamond and precious gemstone jewelry. View Israel’s designs at eternalfinejewels.com and contact Israel directly at 212.869.0845 or israel@eternalfinejewels.com. Showroom consultations by appointment.