DIAMOND CRITIC

Every diamond is unique and therefore has a unique value. When you intend to purchase a diamond, you have to estimate its worth. Roughly speaking, the more rare a diamond is, the more valuable it is as well. The question remains then – how do you measure how rare a diamond is?

The answer is quite simple, the first step is to grade the diamond and measure its different physical characteristics – such as weight, color, clarity and cut. When a diamond is reduced to its set of physical grades, it is much easier to compare it to other diamonds. The value of each specific grade in the scale of a specific characteristic is derived from its abundance in nature (or the market – if you wish to be more economically accurate). We will not go into the details of calculating the exact monetary value from the set of grades at this point. This post will only discuss a very important fact about diamond grading – it is subjective.

Let’s begin with the objective qualities of a diamond. These characteristics do not depend on who measures the diamond, and should always roughly return the same results (with respect to slight measurement accuracy margin of error). These physical characteristics include the diamond carat weight, size and spacial measurements such as the width, height, depth, table size, pavilion angles, etc. These measurements are usually performed with calibrated, high accuracy scales, and do not require any human intervention and judgment for the most part. This means one can theoretically place the diamond in a fully deterministic machine which will scan the diamond and provide the measurements in a fully automatic manner.

The more interesting diamond qualities are of course its non-objective ones. These physical characteristics require the subjective judgment of a trained gemologist after a thorough inspection of the diamond appearance and structure. These characteristics include the diamond color, clarity, cut grade, polish, symmetry and fluorescence. Even though trained gemologists grade in conformance to agreed upon standards and policies, in the end of the day, grading is partly a judgment call. When personal human judgment is involved, you are bound to get different results when letting different people examine the same diamond. It is no secret that there are recorded cases where the exact same diamond has been sent for 2 separate inspections by the same gemological laboratory (even one of the strictest such as the GIA), and these 2 inspections yielded different results. The results usually did not differ much, but this proves that there are definite cases which are debatable and aren’t clear cut.

It is easier to understand why judgment is involved by considering a specific example. Let’s take for instance the diamond’s clarity grade. A diamond clarity grade amounts the internal physical imperfections in the diamond lattice. Such imperfections include black carbon spots (inclusions), cracks, feathers, clouds and scratches. The clarity grade takes many different aspects into account, such as the amount of imperfections, their type, location, size, visibility and proximity. Since no 2 diamonds have the exact same set of physical imperfections, it is easy to see how reducing this endless combination of imperfections into a single grade is not an exact science.

In addition, we should not forget that each grading entity has the liberty to choose its own level of strictness and harshness. What a strict gemologist considers as a Slightly Included (SI) diamond, a more lenient one may consider as Very Slightly included (VS). None of these gemologists can ever be considered wrong, they simply conform to a different scale.

In summary, what should you take from this post? First, don’t be surprised if your diamond receives different grades when presented to different gemologists. Second, when selecting a diamond based on its grades, be sure to check who graded this diamond and inquire as for their reputation and strictness.