Diamond and Jewelry Education
Diamonds
Diamonds are the only gemstone made up of one single element, that of carbon. A diamond is created when its carbon atoms attach to one another in a very specific way, a tetrahedral network in a face centered cubic lattice, under high heat and temperatures. There are a myriad of chemical and elemental factors involved in the formation of diamonds. Few things on earth have undergone such a massive metamorphosis, from where the atoms began to the finished gemstone. All this complexity has contributed to making diamonds one of the most sought after and highly prized commodities on earth. It is no wonder that diamonds have become the symbol of love and commitment.
The appraisal value of a diamond is determined using four key characteristics better known as “The 4C’s”: Cut, Color, Clarity and Carat Weight. What follows is an explanation of each:
Cut: Cut controls the brilliance, or sparkle, of a diamond. If need be, it can hide a multitude of sins. The brilliance and scintillation of a diamond comes from refracted light. With the right proportions, light can pass through the stone and bounce back through the table, resulting in optimal brilliance.
Color: Color classifications are alphabetical, starting from D to Z. D is the whitest or most colorless. Z is noticeably yellow. The graduations are so incremental from one letter to the next that, to an untrained eye, they are indiscernible. They do, however, make a difference on price. When deciding on the color of your diamond, there are many factors to consider. For example, if you were choosing yellow gold for your ring, you would consider a lower color diamond since the diamond would appear whiter against the setting. You may also just prefer the look of a diamond that is technically lower in color, or choose it as a means of staying within budget.
Clarity: Clarity refers to the inclusions within the diamond. Less than 1% of diamonds are graded Flawless (FL), and less than 3% are graded Internally Flawless (IF). Few people can afford these grades, or justify their high value. Thereafter, the grading is Very Very Slight (VVS), Very Slight (VS), Slight (SI), and Included (I). Note that the numbers following the letters depend on the various types and placements of inclusions. Inclusions may exist under the table or out under the crown.
There are a number of types of inclusions. Typically a diamond will have a combination of types. These include: bearding, carbon, feathers, crystals, clouds, needles, pinpoints, twining wisps, indented naturals, and more. See the diagram below for more details. The presence of so many different types of inclusions indicates just how prevalent they are, and how frequently they are part and parcel of the vast majority of diamonds.
Carat: Diamond carat weight is, as the name suggests, a measure of weight in a unit called "carat". Going back through history, this measurement came about because a carob seed was used, due to its consistency of weight, as a balancer to gauge the weight of a diamond. The modern word “carat” is in fact a derivative of the word “carob”. The weight of polished loose diamonds is traditionally rounded to one hundredth of a carat. One carat equals 0.2 grams, 200 milligrams or approx 0.007 ounces.
DIAMOND SHAPES
Diamond shapes refer to the diamond's form, symmetry and proportions. The desired shape can depend on personal style, hand shape, size and even setting preferences. I am sure that for most people, when they envisage their ultimate diamond, the shape is already embedded in their mind. The following are 10 common diamond shapes.
Round Brilliant
The round cut is, by far, the most preferred diamond shape. The cut is also the most optically brilliant because of its 360-degree symmetrical shape. A round brilliant is a great choice if you want the most sparkle and the most enduring classic shape. The round silhouette works with almost every mounting, from classic solitaires to the most avant-garde designs. The round cut began to take shape in the mid-1700s from the old mine cut, through the European cut, the transition cut, with more iterations until, in the 1970’s, mathematically perfect proportions were formulated.
Princess
The princess cut is a modern classic, with clean square lines and beautiful sparkle. The shape of the Princess is distinguishable by its sharp right-angle corners. It is the second most popular shape, after the round brilliant. The cut of this diamond shape combines the step cut of the emerald cut with the triangular facets of the brilliant cut. The princess cut is a great option for someone that likes the sparkle and brilliance of the round brilliant cut but is aesthetically drawn to geometric shapes and symmetry.
Cushion
The cushion cut has a square or rectangular outline with rounded corners. While the preferred shape has a 1:1 ratio, the cushion most often appears with a slightly elongated to elongated shape. The cushion cut is also referred to as an ‘antique square’ or ‘modified cushion’ when cut in the square shape. It has 58 brilliant facets that resemble a pillow shape, hence the name “cushion”. The cushion shape evolved from the "old mine cut", which was developed before the turn of the century. Its purpose was to maintain the maximum amount of diamond weight. The cut has evolved to maximizing brilliance, while maintaining rounded edges and the original pillow shape.
Emerald
The emerald cut is among the most classic of diamond shapes and is usually cut into a rectangular shape. Its clean lines come from step-cutting, or parallel line facets, and it is always cut with blocked (cut) corners. The length-to-width ratios for the emerald cut is typically 1.2:1 - 1.5:1 ratio, meaning that the length of the stone is about 1½ times the width of the stone. However, the emerald can also be cut into a square shape, when it is referred to as a ‘square emerald’, and appear similar to the asscher cut. The emerald cut does not have the sparkle and brilliance of the more faceted cuts. It appeals more to those that appreciate clean lines and a more modern aesthetic. Note, when there are minimal facets and sparkle there is nothing to hide behind. Therefore, when it comes to emerald and asscher cuts, a higher clarity grade is typically desired.
Radiant
The radiant cut is either square or rectangular in shape. Like the emerald cut, the radiant cut is distinguishable by its blocked (cut) corners. The radiant shape is a beautiful combination of the classic emerald cut with the faceted sparkle of the round brilliant or princess cuts, because it combines the step cutting of the emerald with the triangular faceting of the brilliant cuts. This shape has become very popular over the last decade, appealing to those that appreciate its geometric shape with added brilliance.
Oval
The sparkle of the brilliant cut, combined with the elongated shape of the oval, makes the oval shape a perfect choice to accentuate long, slender fingers or give the appearance of longer, slender fingers. The length-to-width ratio of the oval’s dimensions will determine the outline, or what it the diamond will look like when viewed from the top. This shape has become very popular in the last few years, and demand outstrips supply by far.
Asscher
Asscher cut diamonds are simply a variation of the classic emerald cut. Asscher cuts are square in shape and have distinctly cut corners, which add to their geometrical appeal, and make the diamond appear almost octagonal. However, it is the pavilion (bottom part of the diamond) that defines the uniqueness of this shape, which has a "scissor cut" with all facets step-cut down towards the culet (point on the bottom). Asscher cuts will appeal to the purist who leans towards modern and clean lines.
Pear
The pear shape most resembles a ‘teardrop’, with its rounded end on one side and a tapered point on the other. The pear is considered a feminine shape, and the more elongated its shape is, the more slender ones fingers will appear. Pear shaped diamonds can vary in their length and width ratios, with the most common ratios varying between 1.45 and 1.75. Ideally, the length to breadth ratio is determined not only by preference but by the length of ones fingers.
Marquise
The Marquise cut is an elongated shape with tapered points on both ends. Its shape allows the cutter to maximize carat weight, giving the appearance of a larger looking diamond. It tends to flatter the finger, making it appear longer. The most traditional marquise cut diamonds have a length-to-width ratio of between 1.75 and 2.25. Just as with the pear, finger and joint length should be taken into account when deciding on the amount of elongation.
Heart
Heart shaped diamonds have facets that range from 56 to 58. The number of facets on the pavilion varies between 6, 7 and 8. A heart shaped diamond with a length-to-width ratio of roughly 1.00 is considered the most ideal choice. The choice may, however, vary from one person to another. For obvious reasons, this is the quintessential choice for the idealistic romantic!
DIAMOND ENHANCEMENTS
Very rarely are natural earth mined diamonds ‘born’ perfect. The vast majority of diamonds have some kind of imperfection, and usually a combination of different types. Enhanced diamonds have had a particular type of naturally occurring inclusions treated, making them far less visible or even completely invisible. The different types of treatments include:
Clarity Enhancement
Clarity enhanced diamonds have undergone a treatment to visually improve their clarity. Only certain types of naturally occurring imperfections called “feathers” can be clarity enhanced. The enhancement process consists of inserting a clear, materially weightless, microscopic film into the feather. The substance has the same optical properties as the diamond, allowing light to pass right through it. As a result, the imperfection can no longer be detected by the naked eye. The flaws still remain but will no longer be visible. This will typically result in the diamond emitting more brilliance and sparkle.
The enhancement is permanent and completely stable under normal wear and tear conditions. Only two things can wear away this type of enhancement: intense exposure to acid/ammonia and exposure to temperatures exceeding 1400°. Therefore, if you clean your diamond in a fluid, make sure it is an ammonia free fluid. If any work is to be done to your jewelry, disclose to the jeweler that the diamond is enhanced, so he/she will know not to apply the heat of a blow torch. If heat is required, the diamond should be removed from its setting and reset after the necessary work is completed.
Laser Drilling
Laser drilling is used when there are visible black carbon deposits in the diamond. After a microscopic beam is applied to where the carbon deposit is situated, the diamond is boiled in a strong acid solution, which flushes the carbon right out of the diamond. This enhancement is permanent, irreversible, and completely stable.
COLORED DIAMONDS
Many of the most famous diamonds in the world are natural colored diamonds. Diamonds in various shades of blue, yellow, green and pink have been the most sought after and revered stones throughout history. They are, however, some of the most expensive diamonds in the world. Color enhancement can make these special colored diamonds financially accessible.
Color Enhancement
Color enhancement is a common process to improve the color of diamonds. It involves irradiation. During irradiation a beam of electrons displaces the electrons within the diamond. As the atoms restructure themselves, the way the diamond absorbs light is changed, which changes its visual color.
HPHT – High Pressure High Temperature
By reproducing the conditions in nature under which diamonds are created, naturally occurring elements in the diamond are triggered to color the diamond. These elements may be a mineral or, in other cases, they may be environmental. In the latter, high pressure and high temperature changes are applied that replicate the diamond’s voyage to the surface, thus bringing out the naturally occurring nuances in the diamond.
METALS
The metals most often used in jewelry are Gold, Platinum and Silver. Those added in more recent years are Palladium, Tungsten, Cobalt and Titanium, among others.
Gold
Gold is the metal that we associate most readily with fine jewelry. It has been used for thousands of years and can be traced to ancient Egypt, both as personal adornment and currency.
The purity of gold is defined by the percentage of gold in combination with alloys. Its purest form is 24 karat (24kt). The elements most commonly added to make it more durable are copper, zinc, nickel and silver. These elements add their own intrinsic characteristics into the amalgam. In its pure form, 24kt gold is too soft or malleable for use in jewelry.
Purity
| U.S Grade | Composition | European Grade |
|
18kt |
.750 gold/0.250 alloy |
.750 |
|
14kt |
.583 gold/.417 alloy |
.585 |
|
10kt |
.416 gold/.584 allow |
.416 |
Alloys
| Color |
Alloy |
|
Yellow Gold |
Copper & Silver |
|
White Gold |
Nickel, Zinc & Copper |
|
Pink or Rose Gold |
Copper |
|
Green Gold |
Silver, Copper & Zinc |
Yellow and white gold are most commonly used in fine jewelry. White gold is frequently used on prongs for its strength and also aesthetics, since white metal against a diamond appears more subtle. White gold was invented during WWII when platinum was banned from use in jewelry, because of its strength. White gold is rhodium plated to have a whiter, bright finish. Should this plating wear off over time, it can be easily restored to its original white, bright state.
Platinum
Platinum is considered noble and rare. Its natural attributes make it perfect for fine jewelry. Its soft and pliable characteristics contrast its durable and dense nature. Its weight is greater than gold, giving a platinum piece a weighty, substantial feel. Platinum is also hypoallergenic, making it ideal for those with skin sensitivity issues.
Platinum is a naturally white metal which attains a unique, desirable patina over time and wear. In the United States, strict laws control the elements and percentages that are used to alloy platinum. For an item to be considered "PLAT" worthy, it must contain at least 95% pure platinum and its alloys must be sister metals, such as iridium, osmium, palladium, rhodium and ruthenium. Note that platinum can be polished to return it to its original highly reflective state if so desired. Simple buffing with a soft cloth will return its shine and luster.
Silver
Silver, in its purest form, is soft and easily damaged. Therefore, it is most commonly combined with other metals to increase its strength and durability. Traditionally, sterling silver is 92.5% silver combined with 7.5% copper and traces of nickel. This can sometimes cause allergic reactions, which can be overcome to a degree by using rhodium plating. In recent years, silver alloys have been discovered that are less resistant to tarnishing and the need for re-plating.
Palladium & Cobalt
Palladium and cobalt are naturally occurring minerals that are alloyed for use in jewelry. Palladium is one of the metals within the platinum family. Both are hypoallergenic and have their own attributes that include scratch-resistance and durability.
Tungsten, Tantalum and Titanium
Tungsten, tantalum and titanium are all metals that come with individual characteristics that include strength, hardness, lightness, color and scratch resistance. They typically lend themselves to men’s wedding rings because of these attributes.