Advanced Diamond Tutorial Part 1

Diamond Cut…The Basics: Step 1 – Understanding diamond “certs”

You have done it…you have made the decision to step out, take the leap, and buy a diamond. Diamonds, unlike most things that we buy in our lifetime, are items that most of us don’t think about on a regular basis. Unlike stereos, cars, televisions, computers, games, and other mass produced, branded items that we purchase, diamonds are individually unique, fundamentally altered but not manufactured, and subjectively reviewed products.

For example, if you want to purchase a car, you can research the car, read user feedback, professional evaluations, test drive results, trade publication reviews, and more. You can even take one of the cars out for a test drive at your local dealership. Every car of that class is built exactly the same, and although it may yield a slightly different experience to each person that purchases it…its commonalities will overwhelm its differences because all of the cars have been produced using identical parts, manufactured for that specific purpose, and each car has been assembled according to a standardized template.

In contrast, diamonds differ in three specific ways from the average consumer product.

Diamonds are individually unique

Diamonds are mined out of the ground. No two diamonds that are mined are the same. This concept seems basic, however the differences are massive from diamond to diamond. Consider that each diamond is a different size, weight, different shape consisting of a different number of sides or flat surfaces…with each flat surface having a different size, shape, and angle of orientation. In addition, each diamond has different inclusions, cracks, strong points, weak points, molecular crystal structure, color, etc. The difference in characteristics from diamond to diamond is absolutely massive.

Diamonds are fundamentally altered but not manufactured

It is critical to remember that, unlike mass produced products, which are built using identical parts and designed from a master template, diamonds are not manufactured…they are simply altered from a rough state to a finished state using a number of methods, tactics, and devices. Often times finished diamonds have been compared to artists paintings, however this is a poor comparison, since an artist starts with a blank white canvas and all the primary colors. His freedom to create is unlimited, there is no science that will judge the quality and performance of the artists finished painting. In truth, there is nothing that can be compared to the task of transforming a rough diamond into a finished product. A cutter, wishing to take a rough diamond, and transform it into a finished diamond must take the following things into consideration:

He is not working with a blank canvas

The rough diamond is the cutter’s canvas, and he must abide by the laws, restrictions, and unique idiosyncrasies of the diamond rough that he is cutting.

He does not have freedom of creativity

The diamond cutter does not have the freedom of creativity for several reason, the first of which is that, the value of his canvas is determined by its weight, however, in order to unlock the beauty within the rough diamond, he must cut a pattern into the stone, thus causing the rough diamond or “canvas” to loose weight; i.e. value. However, the “cut” of the stone will bring value to it, so the cutter is left to maintain a delicate balance between the value of the weight vs. the value of the cut, making sure that the quality of his cutting does not suffer in an effort to retain weight, nor does he cause the rough, his “canvas”, to suffer undue weight loss as a result of his cutting.

His finished product will be subject to scientific scrutiny

Because diamonds are geometric objects which are designed to reflect light, science can be, and is applied to judge the quality of diamond cutting. This application of scientific and mathematical principles to the analysis of diamond cut quality has lead to the formation of “diamond cut grades” by gemological laboratories around the world. These grades relate directly to a diamond’s visual beauty, which relates to the diamonds consumer appeal, which furthermore relates the demand for the diamond, thereby causing the “cut grade” of the diamond to directly impact the diamond’s value. All of this serves to put the diamond cutter in a box, forcing him to take a predetermined canvas, with its unique restrictions, and produce a product that must fall within a scientifically defined box, while balancing the value of weight vs. cut, both of which are diametrically opposed to each other throughout the cutting process.

Diamonds are subjectively reviewed products

Since diamonds are each so individually unique, there can be no “generalized” grading system, or standardized review system for the cut of diamonds. While it is completely feasible for a critic to write a review on last years model of the BMW 325i…it is utterly impossible for an individual to write a review that will apply to more than one diamond in the world. This vast diversity from diamond to diamond has forced the creation of a set of parameters that attempt to encompass a broad range of proportions and measurements, which all yield similar results, and categorize them as yielding a certain “grade”. These multiple sets of parameters have been defined by different gemological labs around the world, with each set having its own unique interpretations derived from its own scientific processes, and presented to the consumer with its own verbiage and persuasive argument for why it is the most grounded basis for grading.

The reason that it is so important to understand that uniqueness of diamonds, the difficulty with which the cutting process is fraught, the immense variation in cut grading, and the application of scientific tests, is that this understanding is imperative to gaining a full comprehension of diamond “certs”, how they are produced, and why there are so many conflicting opinions in the industry.

The diamond “cert” as it has become known, is in actuality, not a certificate, as the name would suggest, but is rather a report issued by the gemological laboratory that was paid, by the diamond’s owner, to grade the diamond. The report, commonly called the “cert” (this will be referred to as a “lab grading report” for the remainder of this tutorial), is a printed record of the gemological lab’s determinations as to the quality of the diamond. The findings, although based on a scientific grading system, are really a codified representation of a subjective grading analysis that was performed by one or several human graders, each subject to their own grading style and grading predispositions.

Each gemological laboratory has its own individual grading process, that stems off of its unique grading protocol, using its own predetermined course of grading procedures, and employing its own preselected scientific equipment for testing and observing the stone in question.

The fact that there are many different gemological laboratories, each with its own grading system, has lead to a wide variety of “lab grading reports” being issued on diamonds, and presented to the general consumer as absolute fact about the quality of the diamond being purchased.

Of course, at this point, the question must be asked…why are there so many standards…and why has no single standard been determined?  The answer is quite simple. Most consumers, when presented with a “lab grading report”, are wiling to take the information being presented about the stone at face value, many times with little or no knowledge about the gemological laboratory, its grading practices and procedures, or its reputation in the market place. This action by consumers, and the fact that retailers are aware of this fact, has lead to a very simple, yet very detrimental trend in the diamond grading industry.

Consider this…if the average consumer takes a “lab grading report” at face value, without regard to the quality of the grading performed by the lab; and the value of a diamond rests almost entirely, excepting its weight, on areas of subjective grading; i.e. cut quality, color, and clarity; a lab that grades on a loose standard (issuing reports that give diamonds a slightly better grade than the lab’s stricter competitors would give) would allow retailers to present a “lab grading report” that is more “favorable” as well as giving them the ability to charge a higher price for a lower quality stone. The main basis for many labs that grade based on loose criteria is that of consumer ignorance. Diamond cutters, wholesalers, and retailers use these labs to grade their diamonds in an effort to increase the value and salability of their inventory, with the by-product of this effort being added expense to the consumer.

It is imperative that, as a consumer, you have a solid understanding of the major gemological laboratories in the market, their grading systems, and their reputations for the accuracy of the “lab grading reports” that they issue.

Below is a short list of the major gemological laboratories, in the basic order of their grading strictness.

NOTE: It is important to remember that diamond grading is done by humans, which means that human error is a possibility. It is possible for any gemological laboratory to make a mistake in the grading of a diamond.

Diamond Grading Laboratories

  • American Gemological Society Laboratory (AGSL or AGS)
  • Gemological Institute of America (GIA)
  • Gem Certification and Assurance Lab (GCAL)
  • HRD Antwerp
  • European Gemological Laboratories USA (EGL USA)
  • European Gemological Laboratories (EGL)
  • European Gemological Laboratories Israel
  • International Gemological Institute (IGI)

Written by Timothy Andre, Emma Parker & Co.