DIAMOND GRADING

THE 4 C's
In America, we seem to love gemstones in all their forms. But diamonds have the most widespread popularity for us. Premium diamonds are crafted from crystals that have no life to them. A top diamond cutter can transform the unresponsive crystal into a super star. Your task as a consumer is to know what counts and what doesn’t when selecting your dream diamond. A diamond is a serious purchase and, believe it or not, most purchase a diamond without knowing what it is that they have to know in order to be an informed customer. When buying a house, several inspections occur to safeguard you. With diamonds, you can place yourself entirely in the hands of the jeweler or learn what you need to know to avoid problems. No, this is not an article geared to lead you to the perfect diamond but instead, an overview of how diamonds are graded so you can decide what you cannot do without and what you may have to sacrifice to balance your budget.Everyone bases their grading of diamonds on what are called the four Cs. The Cs are (1) carat, (2) cut, (3) clarity and (4) color. Actually, you may want to add two other Cs, namely (5) cost and (6) certificate.

CARAT There is a universally accepted weight system for gemstones. They are weighed in what are called carats (written as ct. or cts.). There are five carats to a gram. That means that a carat is two-tenths of a gram (or 0.20 grams). A carat is further broken down into what are called points. A point is basically one-hundredth of a carat. Therefore, one hundred points is a carat and seventy-five points is a three-quarter carat (0.75 cts. is the way it is written).exactly 25 points and still be a 1/4 carat diamond. When purchasing jewelry, another way of stating diamond weights is to mention what are called total weights (0.90 twt.). This is, of course, all the diamonds’ weight together. Beware of advertisements that exclaim that you will get a 0.25 pt. diamond as that is a mere one-fourth of a point and not a quarter carat diamond.Do the math – a point is one two thousandth of a gram. If a diamond costs ten thousand dollars a carat, then a point is $100. That is most likely the most expensive item you will ever purchase by weight! There are weight thresholds that make diamonds worth more. For example, a single diamond weighing one carat will be worth much more than four 0.25 ct. diamonds with all other factors being equal. A diamond that weighs one or two points under a 0.50 ct. will not be as much per carat as the same diamond weighing 0.50 cts. – actually, you cannot detect if the diamond is a point or two less in weight and these can sometimes be bargains to acquire. You get the size appearance for less money.

CLARITY
Clarity is subjective. Although gemologists are trained to grade diamonds, they can and often do disagree on subjective attributes of diamonds. Rather then provide all the rules, experience and other nuisances that comprise the art of clarity grading, we will provide a few rules-of-thumb.Yes, there is a diamond grading laboratory that issues reports with a clarity grade of SI3. You can logically understand that it is placed between SI2 and I1. Size makes a difference. The bigger the diamond, the more lenient the grader will be. A five carat diamond’s inclusions will be easier to see than if the diamond could be magically shrunk to a one carat size. That being said, remember that you most likely – except for big diamonds – will not see inclusions with your unaided eye (no loupe or microscope) in diamonds graded SI1 and above. A diamond graded SI2 and below will have inclusions that can be seen or located without magnification in a face-up position. The degree that the inclusions are seen, their locations, color and how much they affect brilliance and beauty will determine the actual grade.

In a diamond graded as SI1 the inclusions are usually not seen in a face-up position but only in a face-down position. This is the break-over point for avoiding eagle-eyed critics. Yes, some people can actually see an inclusion in an SI1 stone but the vast majority cannot. Grading from the VS2 grade and up is usually only possible under magnification. The higher the grade, the more money needed to acquire the diamond. You may want to review the above clarity illustration. The lower diamonds have their inclusions plotted in red and the top row have the same inclusions but with a more natural look.

Your decision is whether you want to say that a diamond is a VVS1 or simply that you want the diamond to be what is called eye-clean. Always examine any diamond you are considering to acquire under magnification and then without it. Knowing where the inclusions are will make it easier to tell if they can be seen by the unaided eye. Yes, it is nice to have a great clarity but if you have to budget, grades around SI1 and VS1 and VS2 should be considered.

COLOR
If clarity grading is subjective, color grading is even more subjective. Diamonds rarely are without any color. What is color? Color is really a tint and not a hue when speaking of grading diamonds. Diamonds are usually a shade of yellow, brown or grey. Hue is the actual color – like yellow. Color in diamonds is actually how much of the hue is present – more like grading the tint of a diamond regardless of the hue. The less tint present – the better the color grade. The better the color grade – the more the diamond is worth.

Gemologists use master sets or color grading instruments (or a combination of both). Instruments have some drawbacks. They usually have to be calibrated on an on-going basis. They have trouble with fluorescent diamonds (there are diamonds that fluoresce). The diamond’s cut may affect accuracy as will size. No, human graders are not perfect either. Their master sets may not be accurate. A grader can be affected by the time of the day (one becomes tired as the day wears on), medicines they take and even the colors surrounding them – especially blue.

What are the rules-of-thumb? If the diamond has no perceivable tint in a face-up and face-down position, it may be a colorless grade (D-E-F with D being the best). If the diamond shows no tint in a face-up position but has a perceivable tint in a face-down position, it is most likely a near colorless grade (G-H-I-J). Of course, if a tint is perceivable in both the face-up and face-down positions, it is Very Faint Yellow or lower.

Some K and L graded diamonds can be set so as to mask their color. For these diamonds, we suggest selecting a well cut diamond as that will further mask their color. our decision is whether you can wear a diamond with tint perceivable in the face-up (or mounted position) or not. If not, then what grade do you want and how does that fit your budget?

CUT
There are two interpretations of what this C is – namely (1) the shape or style of cut or (2) the quality of cut. Shape or style can be defined as to whether a diamond is a marquise cut, emerald cut, round brilliant cut, etc. The quality of cut refers to how well the diamond is cut. Each style of cut will have its best and worse quality cuts. However, the only diamond that stands out head-and-showers above the rest for maximizing light return, fire and sparkle is the round brilliant cut. Yes, you can acquire a princess cut that is fantastic in the above attributes but it can never equal the Round Brilliant Cut cut to its best performance.

There are widespread discussions about ideal cut and what that means. “An ideal cut diamond is one that has the highest performance possible for its style of cut” is one suggested definition. However, we are cutters that studied and perfected what many gemologists call super ideal cuts. Therefore, our basic definition of an ideal cut is a diamond that “avoids poor sources of light and directs all the remaining light, some of which has become fire, to the eyes of the viewer in stereo.”

There are charts galore that show light paths entering a diamond and escaping through the back (called the pavilion). This action is called light leakage. The logic is that light that does not return to the viewer will be seen as dark areas. Actually, the diamond displays a dark area whenever it receives poor light (darkness) and transmits it to the viewer. Two obvious poor sources of light are the pavilion and the viewer’s face. If the diamond cutter cuts the diamond to avoid receiving light through the pavilion or from the viewer’s face, they are cutting an ideal cut diamond. In fact, in the commonplace diagrams depicting the best cut diamond, it shows light from the viewer’s face returning to the viewer. That is the worse cut diamond and not the best cut diamond.

You may be wondering what is a super ideal cut diamond. Well, a lot of ideal cut diamonds – verified by diamond grading laboratories as ideal – actually lack fire. They are bright and brilliant but have no flashes of fire. If one cuts a diamond that maximizes brilliance and light return but adds fire – it is a super ideal cut. Diamonds for almost a hundred years now have been cut to look fantastic under the showcase lights in jewelry stores. However, they often look less beautiful in real world environments. A super ideal cut diamond is cut to look best in the real world where you and others will be admiring it every day. In fact, super ideal cut diamonds seem best when other diamonds fail. Frankly, some people cannot detect the difference between super ideal cuts, ideal cuts and well cut diamonds. They can and should purchase diamonds that do not have the premium of quality cutting as it makes no difference to them.