Diamond Lessons

All precious commodities have a system for giving the weight of the items, and this is no different for precious gems such as diamonds. While the cut of a diamond arguably has the greatest impact on the overall desirability of a diamond, the carat has the heaviest impact on its pricing. This is due to the fact that carat refers to the actual weight of the diamond and it is a diamond's weight that is one of the primary indicators for how rare a diamond is. Simply stated, the heavier a diamond is, the more rare it will be and thus the more expense.

It is important to be aware that while the term carat refers to a diamond's weight, it does not refer to its dimensions or shape. The carat weight of a diamond can have an effect on its dimensions and shape, but neither the dimensions nor the shape is wholly dependent on the carat weight. For example, you could find yourself looking at two diamonds that look equal in size as you look down upon them. This does not mean that they have the same carat weight, however. A diamond can be cut to look larger than it is, through increasing its diameter and decreasing its depth, or through other cut techniques. The term carat is used to reference the diamond's actual weight, nothing more and nothing less.

Be also aware that while a diamond is priced in great part based on its carat weight, it is not simply priced on the whole diamond weight. Diamonds are priced on a per-carat pricing system. This means that if a diamond is 3 carats, the cost of the diamond is based on the cost of each carat in the diamond added together, also known as the total carat weight. The cost per-carat is not stationary as you go up in carat size either. For example, if a one-carat diamond were priced at $7500 a carat, its total carat price would be $7500. One might think that a comparable diamond of two carats, with all other factors being equal, would also be $7500 per carat, with the total carat price being $15000. This is not the case. A diamond's per-carat price goes up exponentially based on the carat cost points on the diamond pricing report.

The exponential rise of the per-carat price in the diamond is a result of the fact that the rough for the heavier diamonds is rarer than the rough for smaller diamonds. Due to this, the heavier a diamond is, the exponentially greater the per-carat price will be. The aforementioned one-carat diamond might be priced at $7500 per-carat, whereas the comparable two-carat diamond could be $10000 a carat, or $20000 for the whole diamond. Meanwhile, a three-carat diamond of comparable characteristics could have a $15000 per carat price or a total carat weight price of $45000 for the entire diamond. It is for this reason that oftentimes if you are looking for a large total carat weight for the diamond piece, such as a diamond engagement ring, the best choice might be to have a multiple stone setting, as each stone has its own per-carat price.

It is the rarity of large diamond rough that is one of the primary reasons not all diamonds are ideal cut, as diamond cutters use the maintenance of carat weight as their primary motivation when cutting a diamond, and the ideal cut round is extremely wasteful. It is also useful to note that due to the effect of traveled light distance on diamonds, larger diamonds can often appear to be more brilliant than smaller stones. This is due to the greater prismatic effect resulting from the additional distance the light has to travel within the diamond.

While it is important to be aware that the carat is the measurement of weight for diamonds, this does not provide a useful means of understanding carat weight in relation to other weights. It is simple to understand that a heavy diamond is not going to be heavy in relationship to most items that we are familiar with handling daily, but this doesn't give you a good feel for the weights that you will be dealing with when you are looking into diamonds. This is all the more reason to have a good understanding of the relationships between carat weight and how you can better identify the rough value of a diamond through sight and feel.

"Points" is another term that you will hear to describe the weight of a diamond. The term "points" is used in the diamond industry to indicate diamond measurements that are lower than one carat. In the points measurement, one carat is divided into 100 points. Basically, if you are looking at a half-carat diamond, you may hear it being described as a 50-point diamond. Using the term '50 points' is simply another way of saying that the diamond is a 'half-carat' or 0.50 carats.

To place a carat next to a measurement scale most of us are familiar with, a carat is equivalent to approximately one seven thousandths of an ounce. This one relationship of two different types of weight measurement immediately demonstrates the small sizes that are being discussed when one is speaking of diamonds. To put a little more perspective on this, the largest rough diamond ever found, the Cullinan diamond from the Premier mine in South Africa, was an enormous 3,106 carats prior to cutting. This is a gigantic diamond, yet it is the equivalent of roughly three and a half pounds. Looking at it in such a light, you can see that even an enormous diamond, worth millions of dollars, is still fairly light in comparison to other precious commodities.

The following table will help to further illustrate the carat in comparison to other measurements of weight:

• 1 carat = 200 milligrams
• 1 carat = 1/5^th gram
• 1 carat = 0.20 grams
• 1 carat = 100 points
• 1 carat = 4 grains Troy
• 1 carat = 0.007 ounce
• 141.7 carats = 1 ounce

Another term of weight measurement that may be confusing is the term "Troy". The "Troy" is a measurement of weight that got its name from the French city of Troyes, which became an important trade city during the Middle Ages. The Troy unit of measurement was primarily used for precious metals, drugs and precious gems, such as diamonds. One Troy ounce is the equivalent of 31.1035 grams, or 480 grains.

The grain is the system of weight that was based on, simply enough, the wheat grain (or the barley grain in some ancient cultures). The grain was the equivalent of 1/4^th of a carat, or, more simply, one carat equaled approximately 4 grains. From this use of the grain, you can see that the ancients understood the need for a quantifiable and standard system of weight. The tiny weight measurements involved with the grain further demonstrates their understanding of the need for weight that could accurately and consistently give a weight measurement for diamonds.

As you are deciding on your carat size, remember that the heavier diamonds are not necessarily better than smaller, less weighty diamonds. A smaller diamond with excellent cut, clarity and color will be far more impressive and arresting to the eye than a diamond with a large carat weight that has a poor cut, clarity and/or color. To illustrate the size factor further, think of what you would find more impressive in a car: a large, clunky Oldsmobile, or a small, sleek, Corvette? The same goes for diamonds. There are times when bigger is better, but unless you can afford to have all of the factors going up in relationship with the diamond's carat weight, you are better off choosing the cut, clarity and color of the diamond that you want, and then choosing the carat weight that you can afford.

Another important point to be aware of is the factor of cut-off carat weights. These are also known as 'expense points' and having familiarity with them can not only save you money, but will also allow you to either reach or come close to the carat weight that you desire. Expense points refer to cut off points in carat weight where the cost can rise or decline exponentially. These points are at certain carat weights, such as the following: .50, .75, .90, 1, 1.5, 2 and so on. By staying just below these points, you can have a diamond that is negligibly less in weight, but notably less in expense. What this means is quite simple. If you are looking for a one-carat diamond, rather than choosing a diamond of one-carat or slightly larger choose a diamond that falls just below one carat, such as a .95 diamond. There will be no identifiable difference, especially once the diamond is set, and you could save a large amount of money.

Carat weight plays an important role in the pricing of your diamond, but it should not be the factor that outweighs all others. Each factor should be weighed alongside all others, but carat weight is the first that you can easily decrease in, without sacrificing the overall appearance of the diamond. In the end, the primary function of the diamond is an issue of aesthetics: you want the most beautiful diamond you can attain. It should be towards this goal that you assess all of the factors involved, in order to achieve the balance that will provide you with the diamond that will prove to be the perfect diamond for you.

Carat Expense Guide

There are many factors to take into account when you are looking into buying a diamond, and the carat weight is one of the most important. Within the diamond industry, carat weight is priced through a number of factors, including the color and clarity as weighed against, and with, various carat weights. All of this is published in the Rapaport Report, and diamond dealers use this as a price guide for the per carat price for diamonds.

The Rapaport Report: This is a monthly-published diamond trade paper that offers current per-carat pricing for diamonds. This diamond price report arrives at diamond pricing based on color, clarity and carat weight. Using the pricing guide will give you an idea of the current rate of a particular weight and color of diamond. What it cannot give you is an accurate price for an individual diamond. This is merely a tool for those in the industry to have an idea of what the approximate price for a particular type of diamonds is, and using it will allow you to know the price range that you should expect to see.

There are some problems in using the Rapaport Report as your sole means of determining a diamond's price range. One of the most obvious of these is that the report does not take an individual diamond's unique characteristics into account. While it does account for the clarity, color, the carat weight and certain other important aspects, this can hardly show the entire picture. The report cannot tell you if a particular diamond has a cut that is amenable to your personal tastes, nor can it account for the reflection of the diamond's clarity and color, once set and sitting on your finger. In the end, it is useful to be familiar with the Rapaport Report, but it should not be a strong deciding factor in your choice of diamonds. Use it simply to make certain that you know what price range you should expect, and then look for the dealer who offers their diamonds at a discounted price from that found in the Rapaport Report.

Diamonds are normally thought of as sparkling, scintillating, colorless gems. It is this colorlessness that allows for the incredible and breathtaking play of light that we all have come to associate with the diamond. As you are probably already aware, the color of diamond is primarily dependent on inclusions and foreign matter within the diamond's crystalline structure. This foreign matter absorbs light, rather than allowing it to pass through unimpeded, thus giving some diamonds varying degrees of color.

In the normal range of the diamond color-grading scale, the more colorless a diamond is, the higher it is graded on the scale. In terms of pricing, diamonds with a higher grade will be more costly, while diamonds rating lower on the scale, thus having more color, will normally prove to be less costly. However, when a diamond has a great deal of color, or extremely high color saturation, it may rate the grade of FA, or Fancy. These are the fancy grades of diamond color, and with these the cost of the diamond may actually go higher than the finest of the D grade of diamonds.

In order to establish which diamonds are which colors, diamond color-grading scales have been created. Most of these color-grading scales were not founded with any measure of scientific rigor, however, and so are no longer used. Today, there are far fewer diamond color-grading scales in use, with GIA's being the most used and well respected, allowing anyone to view the results of rigorous testing for color-grading in a written report for a particular diamond. GIA's grading scale ranges from the colorless D to the highly colored Z. It is important to be aware that while most diamonds are graded on a scale measuring the varying degrees of their lack of color, or whiteness, this is not the only sought after type of diamond. There are those diamonds in which various colors are prominent enough to arouse desire for their rarity and distinguished characteristics.

Color is the effect of light wavelengths stimulating the color cones in the retina of the viewer. In the case of diamonds, as they are clear objects, the color that we see from a particular diamond depends on which wavelengths of light's color spectrum are absorbed, if any, as the light passes through the diamond. The flash of color that appears within a diamond is the result of the light that is passing through the diamond having some of its wavelengths absorbed by chemical particles trapped within the diamond's crystalline matrix.

In regards to most diamonds, a lack of color is the most desirable of qualities. What most of us think of when we think of the perfect diamond is of one that shines with a clear brilliance, sparkling and catching the eyes of all who are present. The perfectly clear (or white) diamond is a rarity in the diamond world, and so they carry a large cost. Most diamonds have foreign substances, usually in the form of trace minerals, trapped within their crystalline structure. It is these foreign atoms that absorb certain wavelengths in light's color spectrum, casting a measure of color onto and within the diamond, thus producing a certain color in the diamond. The actual color of the diamond is therefore dependent on which foreign element or elements are present, as well as the quantity of the foreign element(s) within the diamond's structure.

A diamond's color is rooted in the earth from which it comes. Diamonds are formed over millions of years, as the result of carbon deposits placed under enormous geologic pressure and incredible heat. Throughout the growth of the diamond, and the diamond's eventual push towards the earth's surface, the diamond is subjected to naturally occurring radiation, geologic movement that can twist the crystalline structure of the diamond, and the potential addition of impurities. During the diamond's formation nearby elements of other minerals are often mixed in with the carbon deposit. As the diamond deposit cools, and the crystalline structure that we recognize as a diamond begins to grow, some of these other minerals become trapped within the growing crystal.

In fancy colored diamonds, such as in Canary yellow diamonds, where there are large numbers of nitrogen atoms scattered throughout the diamond. These nitrogen atoms absorb light, giving the Canary yellow diamonds their vivid yellow color. The same goes for all of the other color diamonds, simply with alternate atoms trapped within the diamond.

The inclusion of foreign atoms is just one way in which diamonds can become colored during their formation. They can also become colored due to irregular growth patterns arising from pressure as the diamond is forced to the surface of the earth, as is found in certain pinks and blues. In the case of greens, it is the natural radiation found within the earth that gives them their color.

Once the diamond is fully formed and has been forced to the surface of the earth, these trapped foreign objects, such as trace mineral deposits, gases and liquids, become a part of the diamond's crystalline structure. The diamond's crystalline structure is clear, or colorless, and so does not have the ability to absorb wavelengths of light. This is why they are so bright and are able to scintillate. It is trapped objects, such as nitrogen, which absorb certain light wavelengths, making the diamonds have color.

Much of the newly found interest in fancy color diamonds is due to the discovery of a relatively large load of pink diamonds in the Argyle mine in Australia. While the quantity of pink diamonds coming out of the mine is still miniscule in comparison to the quantity of other diamond types, it is still far more than had been available for years. Of course there is another aspect that needs to be understood concerning the current interest in fancy colored diamonds, and that is the exclusivity of fancy colored diamonds. Fancy colored diamonds are far more rare than any other diamond type. It is this rarity that adds to their value, as those who possess a richly colored diamond hold a king among kings in the gem world.

Tips on Colorless Diamonds

It is important to be aware that as you step down the color grade scale, the diamond's overall cost will decrease. It is also important to note there is a significant reduction in cost per carat as you move from D to E, and from F to G, and so on. Knowing this, you should carefully and honestly assess what grade of color you will be happy with. Always keep in mind, the majority of the untrained population can hardly distinguish the difference between a GIA G and H, and likewise a GIA F and G, so if they look the same a letter grade difference in color could translate to hundreds of dollars in savings.

Another factoid concerning color, due to the differences in training and diligence amongst the laboratories some grade more accurately than others. The price difference between an EGL D and a GIA D is due to the lack of accuracy on EGL's part. Typically an EGL or IGI certificate will grade color inaccurately by one to two color grades making the pristine D color drop down to the bottom of the "colorless" group as an F. This is really most important when considering diamonds that are closer to the lower color grades, such as a G, which if graded by EGL could have a slight yellow tint (which is not indicative of a true G color diamond).

Finally, consider the setting of the stone itself. Once the stone is set its level of colorlessness can be enhanced or detracted from, depending on the metal used for the setting and the size of the stone. A well-chosen setting can make a stone with faint yellow coloring appear to be colorless. In other words, a white metal can enhance warm yellow tones in a diamond, whereas yellow gold can cause a diamond to appear more colorless than it actually is.

There are many aspects of a finished diamond that are dependent on the diamond cut, and one should be somewhat familiar with these. The most important of these include: brilliance, fire, number of facets or proportion, symmetry, polish, desired weight, and the diamond's final shape.

The cut of a diamond is, to be blunt, the approach and results of cutting the raw, rough diamond into the polished, shining stone that most of us are familiar with. More specifically, cut refers to the effectiveness of a diamond in reflecting and refracting light.

Proportion: The proportions of a diamond include the number of facets cut into the diamond, the size of the facets, and the length and width of the diamond. The ideal cut of a round brilliant cut diamond was first established by Marcel Tolkowsky at the beginning of the 20th century. For example, a diamond that is wide, but not deep enough in relation to its width at the girdle or table, will leak light out of the bottom (or culet) of the stone. On the other hand, a diamond with too deep, or long a cut, in relation to it's width, will leak light out of its sides. A diamond with the correct proportions will better allow light to pass unimpeded back to the eye, with its full color spectrum intact.

The ideal cut was designed to provide standard, mathematically accurate ratios of table size (the top, and largest facet of a stone), diameter (the diamond's width at the girdle), crown (the diamond from the girdle up), pavilion (the diamond from the girdle down), culet (the bottom, and smallest, facet of a diamond), girdle (the belt at the widest portion of the diamond) and depth (the entire diamond height from table to culet or top to bottom).

Polish: The polish of a diamond is fairly self-explanatory, in that it is the finished polish on a diamond's surfaces, or facets. The facets must have a good polish in order to most effectively reflect light that passes over the diamond. A poorly polished facet or facets can prevent a diamond from not only failing to properly reflect the light that is flashing over it, thus creating a dulled surface look, but poor polish can also cause a diamond to be diminished in its ability to allow light to pass into and through it, thus diminishing its fire and brilliance. In effect, a poor polish can ruin an otherwise spectacular diamond. A diamond's polish should produce smooth, clean and flat surfaces, so that the diamond's play of light is utilized to its greatest effect.

Symmetry: The term symmetry refers to the placement of a diamond's facets. The facets themselves are the flat surfaces that we are familiar with when we think of a diamond. These surfaces must be aligned in just the right orientation to one another, and they must be sized in relation to one another. If a diamond has proper symmetry, this indicates that its facets are all the proper size in relation to one another, and that there are the proper number of facets, in relation to the size and desired effect of the diamond.

Good symmetry provides the kind of light reflection that produces the dazzling light display that we know as "scintillation". It is these scintillating flashes of light that most of us think of when we think of the perfect diamond. A diamond with poorly aligned facets will have poor symmetry, and will not provide the kind of bright flashes of reflecting light that most of us would desire from a diamond.

Weight: In the case of such diamonds, the rough diamond is cut to best accentuate the particular qualities of the diamond. For example, a diamond may be cut for greater depth, or greater width, so as to allow for a larger carat weight. While these diamonds may not have the brilliance or fire of an ideal cut diamond, their weight allows them to have greater value than they would otherwise have should they be cut down to an insignificant size for the sake of an ideal cut.

The desire for a particular carat weight also comes into play in the choice of cut for a diamond. While the ideal cut may seem to be what is desired above all, this is not actually the case. There are many rough diamonds that, due to various reasons such as cleavage points, and inclusions, would be diminished to insignificant carat weights should they be cut to ideal proportions.

Shape: When a diamond is cut, the diamond will have a particular shape. This shape is usually determined by the motivation of the cutter, to supply the largest and best quality diamond; which means he must follow the structure of the diamond's original rough. There are numerous shapes for diamonds, with no particular shape being better than any other, although the current market demand is for round brilliant and princess cut diamonds. However, keep in mind the shape of a diamond that is right for one person may not be right for another.

Brilliance: The brilliance of a diamond is a direct result of a diamond's cut. Brilliance itself is simply what is implied in the word; the brilliant shine of light that a particular diamond is able to reflect and refract. A high brilliance tends to be the main goal of a diamond cutters art, as a brilliant stone is often regarded as the most desirable of diamonds.

The ideal cut was meant to provide a cut that maximized the potential brilliance, or light producing qualities of a particular diamond. Essentially, light that passes through a diamond that is cut well will allow more of the light to come back out of the crown, or top, from which it entered, with the entire color spectrum intact.

The intact color spectrum is the internal brilliance that we see when we are looking at a diamond with a good cut as the light is passing through it. The light that does not pass through the diamond, the reflected light, is its luster, or external brilliance, and is the result of the light reflecting off of the diamond's facets. The white light that is known as brilliance is a result of the pavilion's cut.

Fire: Fire, like brilliance, is a description of the light qualities of a diamond. In the case of Fire, however, the light quality that is being described is the amount of light that is seen to be emanating from the center of the diamond. Fire is a descriptive term used to illustrate the colorful splash of light that the light passing through a diamond produces in the center of the diamond itself.

As with the light properties involved with brilliance, fire is the result of light being split apart into its color spectrum within the diamond, whereas brilliance comes from the intact color spectrum coming out of the diamond. Fire is what is seen of the color spectrum of light as it is broken up into its various bands while still within the diamond. The full spectrum color that is known as fire is the result of the cut of the crown.

To save some money without affecting the beauty of the diamond it is wise to look for diamonds that fall just outside of the "ideal cut" parameters. To the unaided eye, a diamond of less than ideal proportions can look just as good as an ideal cut.

Once a diamond is set, any differences between a good, very good and an ideal cut diamond are often lost to the untrained eye. Also, a diamond that is not ideal proportions can have a lower depth % in relation to its width, and will actually make the diamond appear to be larger than its ideal cut counterparts. It is in this way that a small stone can be made to appear to be much larger and save you money.

There are also those who have come to regard the Sarin report as a superior determinant in the quality of a diamond. Thinking in this manner will only cause you to spend more money than is necessary. The Sarin machine measures the actual proportions and dimensions of a diamond, and this measurement is placed against the ideal cut ratios and measurements. Again, while the Sarin report can give you an accurate reading of the diamond in question, it does not mean that you will ever be able to see the difference between a very good or good diamond, as compared to the measurements for an ideal cut diamond.

Most diamond grading associations use the following scale for cut grading: Ideal, Premium, Excellent, Very Good, Good, Fair, and Poor. The cut grade of diamonds is a difficult process for anyone to easily assess, and yet the cut grade is one of the most important factors in choosing the right diamond. For example, one may find a round brilliant diamond with a grading from GIA of very good. This would seem like the perfect choice, but what exactly is GIA basing the Very Good on? It is also important to be aware that a cut grade report does not assess or give a value to a diamond. The cut grade report is an expert opinion on the quality of a specific loose diamond, as measured through a number of measurements and expert examination, given by an independent gemological laboratory.

Proportions

Each type of cut, whether it be round cut, princess cut or any other, has its own proportions particular to that cut. This is due to the fact that each cut has its own particular light qualities ideal to that particular cut. For example, the step cuts, such as the emerald cut, has long, plane-like surfaces. These types of broad rectangular facets would, quite obviously, not be the ideal, or even the choice of cuts in order to create the brilliant scintillation associated with the brilliant cuts, such as the ideal cut round. However, for those seeking a warmer fire and glowing light display, as well as a diamond with a longer, and often times larger looking appearance, the emerald cut, which also can enhance short fingers, can be the ideal choice. Therefore, it is not a single cut grade that is used when evaluating a diamonds grade of cut. The grade of a diamond's cut is dependent not simply on the effect of the cut on the light properties of the diamond, or on the adherence to the ideal cut ratios. The cut grade is dependent on the particular cut that diamond is filed under, i.e. emerald cut, princess cut, etc.

Polish and Symmetry in Evaluating Cut Grade

Another aspect of the cut grading is the polish and symmetry achieved in the diamond's cut. The cut of the diamond could be perfect in all regards, with all of the angles properly cut, the facets cut and angled properly, and the depth/table percentage perfect. However, even with all of that being correct, if the polish or symmetry of the diamond is off, the diamond's cut grade will suffer.

The polish of the diamond is essential to the cut grade in that it represents the ease of light to enter and exit the diamond. If the polish of the diamond is poor, the play of light emanating from the diamond's crystalline structure will neither receive the light it requires in order to produce its full effect, nor return the light to the eye with the color spectrum fully in tact. In short, the polish of the outer facets of the diamond is just as important to the cut grade as the diamond's proportions.

The symmetry of the diamond is just as important as the polish in formulating the final cut grade. The symmetry refers to the placement of the facets on the diamond's face. Even should all other aspects of the diamond be absolutely excellent, a poor placement of the diamond's facets, or the poor angling and sizing of the facets, can ruin a diamond's cut grading. It is extremely important to the diamond's light effect to have each and every facet evenly placed, sized according to the particular needs of the cut, and angled at the proper degrees.

As has been mentioned, the proportions for even the ideal cut round diamond can vary, depending upon which standard (American Standard, Practical Fine Cut, Scandinavian Standard) is used when the diamond is being graded. AGA, American Gemological Association, is considered to have the highest standards for diamond cut grading; yet they may rate a diamond that you find to have an excellent cut as simply "Good." Choosing the diamond within your budget that you find the most desirable, and then having your diamond's cut appraised by an independent appraiser is the best solution.

Ideal Cut (applicable primarily to round brilliant, and princess cut):

Many people hear the term "ideal cut" and immediately believe that this is the zenith of diamond cuts. The ideal cut can be the perfect choice, as it is the diamond cut that is designed for maximum brilliance in light quality. While the ideal cut is a good choice for many different occasions, it is not necessarily better than any other cut. The ideal cut is an excellent, and safe, cut to choose when looking for a diamond. It is not, however, the only cut in diamond to consider when looking into diamond cut. Cut is something that must be weighed along with other factors. It is also important to be aware that only the round and princess cuts are specified for the ideal cut measurements.

Below are the various "round brilliant ideal cuts" and their proportions:

	Crown height	Pavilion depth	Table diameter	Girdle thickness	Crown angle	Pavilion angle
American Standard	16.2%	43.1%	53.0%	2.5% 34.5°	40.75°	N/A
Practical Fine Cut	14.4%	43.2%	56.0%	N/A	33.2°	40.8°
Scandinavian Standard	14.6%	43.1%	57.5%	N/A	34.5°	40.75°
Eulitz Brilliant	14.45%	43.15%	56.5%	1.5%	33.36°	40.48°
Ideal Brilliant	19.2%	40.0%	56.1%	N/A	41.1°	38.7°
Parker Brilliant	:10.5%	43.4%	55.9%	N/A	25.5°	40.9°

The ideal cut has its origins with the mathematician and theorist, Marcel Tolkowsky, who, in 1919, published his findings in his quest for what he saw as the ideal proportions for cutting a diamond. What he used for his measurement of ideal was his measurement of light loss within a diamond. This means that when light enters a diamond from above, or the table, in order for it to provide the greatest light show, it should return back to the eye through the table. In other words, he felt that a diamond has its greatest effect when the light entering a diamond returns to the eye from the same place it entered the diamond, without any of the light leaking out of any of the other facets. It was to affect this display that he developed the mathematical equations, based on the angles of the crown, pavilion, table, depth and width, in relation to one another, that would achieve what he saw as the ideal. This ideal produced a brilliant diamond, what we now know as the category of brilliant diamonds, which include the round brilliant and the princess cut. In time, the ideal cut came to be regarded as the optimum selection in diamond cuts. This did not happen overnight, however, and many other cuts preceded the ideal cut, with many others coming after it.