Anatomy of diamonds

The diamond's distinctive chemical composition and crystal structure make it a unique member of the mineral kingdom.

The way a mineral forms helps determine its identity. Diamond forms under high temperature and pressure conditions that only exist at a depth range of about 100 miles below the Earth's surface. Diamond's crystal structure consists of the carbon atoms bonded essentially equally in all directions. The result is that diamond is so hard that you can't scratch it unless you use another diamond.

Without any of these factors, diamond could be just another mineral. Fortunately, this special combination of chemical composition, crystal structure and formation process gives diamonds the properties that make them exceptional.

Diamond is now recognized as the birthstone for April on almost all modern birthstone lists.

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When you buy a diamond, you are drawn to the jewelry counter by its brightness and sparkle, and remain captivated long after you have purchased your diamond. Achieving maximum brightness and sparkle requires excellent cutting technique, which is reflected in the diamond's cut quality. Of the 4Cs, no other "C" has more influence on the appearance of a diamond.

When people think of "cut," they often think of the shape of a diamond rather than its cut quality. Cut is all about the fire, luster, and brightness of a diamond. As a value factor, it refers to a diamond's proportions, symmetry, and polish; the factors that determine cut quality, or the fourth "C."

When evaluating the cut quality of a diamond, a number of complex factors are taken into account: its proportions, the symmetry of its facet arrangements, and the quality of its polish or finish. Cut quality reflects the appearance of diamonds.

Table : The table is the top horizontal facet of the diamond. The average table size is expressed as a percentage of the diamond's average girdle diameter. While a diamond rated Excellent quality will have a table size between 52 and 62 percent, other proportions are also important.

Total Depth : The total depth of the diamond from the surface of the table to the culet, expressed as a percentage of the average girdle diameter.

Pavilion depth : The pavilion is the lower part of a diamond from the bottom of the girdle to the culet. Pavilion depth is expressed as a percentage of the average girdle diameter. A pavilion depth that is too shallow or too deep allows light to escape from the side or bottom of the stone. A well-cut diamond will direct more light upward through the crown.

Pavilion Angle : Pavilion angle is another important dimension of the stone, especially in relation to the brightness of a diamond. This is the average of the angles formed by the main facets of the diamond's pavilion and its girdle plane. This should be between 40.6 and 41.8 degrees to be considered "excellent", assuming other parameters also fit into their proper ranges.

Crown Height : The crown is the upper part of the diamond from the top edge of the girdle to the table. The average crown height is expressed as a percentage of the average girdle diameter. It can affect both the dispersion and brightness of a diamond.

Crown Angle : The crown angle is the angle formed where the bezel facets meet the girdle plane. The crown angle in a well-cut diamond is between 31.5 and 36.5 degrees. The crown angle has a major impact on the open appearance of a round brilliant cut diamond. The best range of crown angles provides a route for light scattering to exit as well as additional contrasting directions for light to enter.

Star Length : The horizontally projected distance from the point of the star facet to the table edge, relative to the distance between the table edge and the girdle edge. A well-cut diamond will be between 40 and 70 percent if other parameters are within the correct ranges.

Girdle Thickness : The girdle is the middle part of a diamond, a narrow section that separates the crown from the pavilion and acts as the diamond's setting edge. Girdle thickness is described as a range from the thinnest to the thickest areas. A thick girdle is less desirable because it adds unnecessary weight to the stone where it matters least (making the diamond appear smaller). An extremely thin girdle is sometimes called a knife edge and results in a diamond that is more fragile and prone to chipping. Therefore, a girdle that is "medium to slightly thick" is preferred.

Lower Girdle / Half Facet Length: This ratio is measured by calculating how long the lower girdle facets are relative to the length of the pavilion. This defines the contrast of a round brilliant cut diamond, which controls the brilliance of a diamond. The well-cut diamond is between 65 and 90 percent. Diamonds with longer lower half facets have slightly more scintillation.

Culet : The culet is the small facet at the bottom of a diamond designed to prevent chipping and abrasion to the point. The size of the culet can affect the appearance and is referred to as the average width of the facet. The size is expressed as none, very small, small, medium, slightly large, large, very large and extremely large. When there is no culet, it is sometimes referred to as a pointed culet. Preferably, the culet is not visible to the naked eye, and when it is described as none (no culet), it falls in the excellent range.

Four Cs – Carat, Clarity, Cut, Colour

CARAT (ct.)

Diamonds are sold by the carat (represented as ct.), which is actually a unit of weight, although most people think of a carat in terms of size. The word " carat " comes from the carob seed, the original unit of measurement for diamond dealers. A carat today is exactly 0.2 grams (about the weight of a paper clip). Carat weight has nothing to do with the similar-sounding karat, which refers to the purity of gold.

Two diamonds of the same carat weight can cost very differently based on other factors (such as cut, color, and clarity). If you understand the importance of carat weight, you know your partner. If the recipient's heart is set on a certain size diamond, carat weight will likely be the most important factor in your search until the desired size is achieved, at which point other criteria will become more important. Most women can tell you the carat weight and shape of their ideal diamond, and most men can tell you the price.

As the carat size of a diamond increases, the price of the diamond increases at an increasing rate. Why? Because the larger the diamond, the rarer it becomes. Less than one in a million rough stones mined is large enough to produce a finished 1-carat diamond.

It's important to note that not all diamonds are the same carat weight. Due to differences in depth and cut, two diamonds with identical diameters can actually be two completely different sizes. Therefore, it's possible to buy a diamond that looks larger than another that may actually have a smaller carat weight. When buying a diamond, consider the length, width and depth of a stone, as well as the diamond's surface area (the part that actually shows when the diamond is set).

CLARITY & COLOR

A flawless diamond with little to no imperfections is often desired due to their rarity, but they are also the most expensive, so it is important to remember that diamonds are often formed with slight imperfections.

These imperfections are called "inclusions" and usually occur during the diamond's crystallization period in the earth or due to the stresses of mining and processing. Inclusions are anything from tiny white dots to dark spots, cracks or scratches. The fewer inclusions, the more valuable a stone is. Clarity is graded using 10x magnification. This means that the object being viewed is ten times its actual size. The diamond grader looks at clarity characteristics in terms of the type and number of features, as well as their size, color and location.

There are six main quality grades for diamonds. The highest is called Flawless (denoted "FL"), followed by the next best grade, Internally Flawless (IF).

What is VVS clarity?
Diamonds with VVS clarity have very minor imperfections that even trained professionals cannot easily detect with a magnifying glass or microscope.

The VVS grading range is divided into two subclasses: VVS1 and VVS2, with VVS1 being the higher class.

What is VS Clarity?
Diamonds with VS clarity have inclusions that are usually difficult to see under 10x magnification. A small number of these imperfections may be more easily visible, but they are still tiny. Like VVS clarity, the VS grade is divided into VS1 and VS2.

VVS diamonds have smaller inclusions
The main difference between VVS and VS clarity is the size of the inclusions: VVS diamonds have smaller and less visible flaws. Even if you look at these stones under a microscope, it is usually difficult to see inclusions.

VS diamonds, on the other hand, have some inclusions that are easily visible under magnification. Most flaws are still microscopic, but at least one or two of them are larger and easily visible with a jeweler's loupe. Remember, these are still inclusions and are not visible to the naked eye.
A superior cut or color can make a VS diamond more expensive than a VVS stone, so you should evaluate other quality characteristics as well. All else being equal in terms of affordability, VS clarity is the clear winner.

Remember that the differences between VS and VVS can only be seen with a microscope or a 10x magnifying glass. You cannot tell them apart with the naked eye.

Cut (diamond cut)

People often use the words "cut" and "shape" interchangeably when talking about diamonds. However, these two terms have slightly different meanings. Shape refers to the general outline of a stone. Although a specific cut implies a specific shape, the term cut technically refers to the number, arrangement, shape, and proportions of a stone's facets. A diamond's shape tells you what a stone looks like, while its cut gives you information about how that shape was achieved by cutting.

Technically, two diamonds can have the same or similar shapes, but their cuts are considered different if their facets are arranged or shaped differently.

Ideal diamond cuts

Although there are a number of diamond cuts on the market, these are the ones most likely to be seen when purchasing jewelry:

Round cut
The round cut is perhaps the most popular diamond cut sold today. This is the cut specifically designed to maximize brilliance. Because of this, flaws and yellow tones are less visible in round cut diamonds than in stones of other cuts. Many consumers consider the round cut to be the classic diamond cut.

Princess cut
The princess cut is similar to the round cut in that both are brilliant cuts, but the princess cut has a rectangular outline instead of a round one. Although not as brilliant as the round cut, the princess cut is a good alternative to it if you are looking for a diamond that has a square or rectangular shape while also having a good amount of sparkle.

Emerald and Asscher cuts
The emerald cut is a rectangular step cut with trimmed corners, and its square variation is called the "Asscher cut." The emerald and Asscher cuts differ only in outline, but the shape and arrangement of their facets are the same. These cuts do not have as much brilliance as the round or princess cuts, and therefore any imperfections or tones are more visible in the emerald and Asscher cuts.

Cushion cut
Cushion cut diamonds look rectangular or square, but their corners are rounded, making the shape of the stone look like a cushion. The cushion cut belongs to the group of brilliant cuts.

Radiant cut
The radiant cut has a rectangular or square shape with cut-off corners. This is another brilliant cut that is often compared to the cushion cut. The radiant cut shares some features that are characteristic of the emerald cut, and this commonality leads some people to classify the radiant cut as a mixed cut.

Oval cut
The oval cut is another brilliant diamond cut and can be considered a modified version of the round cut. An oval cut diamond is a great choice if you want your jewelry piece to give the impression of length, especially if the stone is mounted in a ring.

Marquise Cut
Marquise cut diamonds have an oval outline but two pointed ends. These sharp points are particularly susceptible to chipping and should be properly protected by the setting when the diamond is mounted in a piece of jewelry.

Pear cut
The pear cut has an oval shape and one of its ends is pointed, making the outline of this cut look like a teardrop or pear. Pear cuts combine features of the marquise cut and the oval cut. If you have a pear-shaped diamond, make sure its sharp end is protected when you set it in a piece of jewelry.

Heart cut
The heart cut looks very similar to the pear cut, but the rounded end of a heart-shaped diamond has a gap. When purchasing a heart-cut diamond, make sure the left and right parts are symmetrical.

Trilliant cut
The Trilliant cut has a triangular outline. The ends can be pointed or rounded. If they are sharp, they can chip easily, so they should be protected accordingly when worn. Trilliant cut diamonds are often used as side stones, but can also be worn as center diamonds.