The GIA 4Cs of diamond quality will help you learn how to buy a diamond. This basic knowledge will not only unlock the mystery of a diamond’s quality, it will also help you understand a diamond’s value and price.
]]>The GIA 4Cs of diamond quality will help you learn how to buy a diamond. This basic knowledge will not only unlock the mystery of a diamond’s quality, it will also help you understand a diamond’s value and price.
No matter how beautiful a diamond may look you simply cannot see its true quality. Knowing more about the 4Cs of diamond quality will help you learn how to buy a diamond. The 4Cs provide you with the information you need to know the diamond’s actual quality.
Your jeweler should be armed with expert training, open to questions and able to explain how to buy a diamond in clear, simple language. A jeweler’s professional training can help you evaluate how knowledgeable he or she is. Preferably, their training comes from a highly recognized and internationally accredited program, such as the GIA Graduate Gemologist (GG) or Applied Jewelry Professional (AJP) diploma programs. As your personal diamond-buying guide, an educated jeweler will not only explain the 4Cs of Diamond Quality to you, but will also be able to demonstrate the differences between apparently similar stones. They will encourage you to compare a number of diamonds that fall in your budget.
A diamond grading report from an unbiased, scientific source such as GIA is more than important information, it’s proof of what you are buying. The differences in diamonds can be so subtle, even a trained jeweler can’t recognize them without lab verification. Insist that any diamond you buy come with an indisputable verification of its quality.
Once you’ve purchased the right diamond, have it appraised and insured. Appraisers and insurers rely on diamond grading reports to accurately evaluate the value of gems. As an additional measure, consider having your diamond laser-inscribed with its GIA report number, to provide verification if it is ever lost or stolen.
The prestigious GIA Graduate Gemologist diploma program teaches jewelers the science and technical knowledge needed to deal with the entire spectrum of diamonds and colored stones. The distinguished GIA GG designation at the end of an individual’s name is instantly recognized around the world as the mark of a senior professional in the jewelry industry.
The GIA Applied Jewelry Professional credential is a professional development program designed specifically for sales associates and provides them the essential product knowledge to communicate the right information on how to buy a diamond to their customers.
The GIA Cut Scale is used for round brilliant-cut diamonds and consists of 5 grades, ranging from excellent to poor. You may think cut is the shape of a diamond, like square cut or round. However, there is much more to cut than the basic shape.
Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond’s cut as shape (round, heart, oval, marquise, pear), but what diamond cut actually does mean how well a diamond’s facets interact with light. Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry and polish deliver the magnificent return of light only possible in a diamond.
How a diamond is cut and polished directly affect the amount of sparkle and brilliance that comes off the stone when it interacts with light.
How light strikes the surface, how much enters the diamond, and how and in what form light returns to your eye. A polished diamond's proportions affect its light performance, which in turn affects its beauty and overall appeal.
Achieving the best cut for a diamond reflects in the stone’s final beauty and value. And of all the diamond 4Cs, it is the most complex and technically difficult to analyze. To determine the cut grade of the standard round brilliant diamond – the shape that dominates the majority of diamond jewelry – GIA calculates the proportions of those facets that influence the diamond’s face-up appearance. These proportions allow GIA to evaluate what the best cut for a diamond is, by studying how successfully a diamond interacts with light to create desirable visual effects, such as:
GIA’s diamond cut grade also takes into account the design and craftsmanship of the diamond, including its weight relative to its diameter, its girdle thickness (which affects its durability), the symmetry of its facet arrangement, and the quality of polish on those facets.
The GIA Diamond Cut Scale for standard round brilliant diamonds in the D-to-Z diamond color range contains 5 grades ranging from Excellent to Poor and is the definitive scale for classifying diamond cuts.
The distance from the bottom of the girdle to the culet is the pavilion depth. A pavilion depth that’s too shallow or too deep will allow light to escape from the side of the stone or leak out of the bottom. A well-cut diamond will direct more light through the crown.
Larger diamonds are more rare than smaller diamonds. So all other factors being equal, a single 1-carat stone would be worth more than four 1/4-carat stones put together. However, the value of a diamond is determined by considering all 4Cs, so bigger is not always better.
All else being equal, diamond price increases with diamond carat weight because larger diamonds are rarer and more desirable. However, two diamonds of equal carat weight can have very different values (and prices) depending on three other factors of the diamond 4Cs: Color, Clarity, and Cut.
To put it simply, diamond carat weight measures how much a diamond weighs.
A metric “carat” is defined as 200 milligrams. Each carat is subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its ‘points’ alone. For instance, the jeweler may refer to a diamond that weighs 0.25 carats as a ‘twenty-five pointer.’ Diamond weights greater than one carat are expressed in carats and decimals. A 1.08 carat stone would be described as ‘one point oh eight carats.’
In order to understand what a diamond carat measures, it would help to know the origins of the modern carat system. Carat weight started with the carob seed, when early gem traders used the small, uniform seeds as counterweights in their balance scales. Today, the carat is the same milligram weight in every corner of the world.
Some weights are considered “magic sizes” – half carat, three-quarter carat, and carat. Visually, there’s little difference between a 0.99 carat diamond and one that weighs a full carat. But the price differences between the two can be significant.
Because diamonds form under tremendous heat and pressure, it is extremely rare to find a diamond with no internal or surface-reaching inclusions. Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth.
Inclusions are a byproduct of its formation, and actually help gemologists separate natural diamonds from synthetics and lookalikes. The GIA Clarity Scale includes 11 clarity grades, ranging from flawless to I3.
Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. If you are trying to determine what is the best clarity for a diamond, remember that no diamond is perfectly pure. But the closer it comes to purity, the better its clarity.
The GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades.
Flawless indicates that there are no inclusions or blemishes visible at 10x magnification. A grade of I3 is for diamonds with inclusions that are obvious to the naked eye.
Diamond graders at GIA labs use a 10x magnification loupe and a microscope to see and plot the inclusions. Since no two diamonds are exactly alike, this unique plot helps identify a particular stone.
During this step, graders also look to see if there is any evidence that our diamond was treated to improve its clarity and any treatment will be noted on our diamond's report.
Many inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond grader. To the naked eye, a VS1 and an SI2 diamond may look exactly the same, but these diamonds are quite different in terms of overall quality. This is why expert and accurate assessment of diamond clarity is extremely important. Knowing what diamond clarity truly means helps you understand the factors that contribute to diamond quality and price.
Like the color scale, GIA’s clarity grading system developed because jewelers were using terms that could be misinterpreted, “loupe clean” or “piqué.” Today, even if you buy a diamond somewhere else in the world, the jeweler will most likely use terms like VVS1 or SI2 to indicate the clarity of a diamond, even if his or her language is French or Japanese instead of English.
Small crystals can become trapped in a diamond when it’s forming. Sometimes as a crystal grows, it can develop irregularities in its atomic structure. The size, position and visibility of inclusions can have a significant impact on diamond clarity.
When it comes to Diamonds the less color, the higher the grade. The GIA Color Scale classifies Diamonds from D (colorless) to C (light-yellow or brown).
Each letter grade represents a range of colour and it is a meassure of how noticible a colour is. Trully colour-less Diamonds are very rare.
Most Diamonds used on Jewelry are newly colour-less, with tints of yellow or brown.
To provide a universal basis for color comparison, GIA gemologists meticulously assembled a set of master stones representing the colour grades on the GIA scale.
Understanding what diamond color means helps in choosing the right diamond. Interestingly, the diamond color evaluation of most gem-quality diamonds is based on the absence of color. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA’s D-to-Z diamond color-grading system measures the degree of colorlessness by comparing a stone under controlled lighting and precise viewing conditions to masterstones of established color value.
Many of these diamond color distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price. Hence, it is important to get a GIA expert’s opinion in evaluating the best color for your diamond.
Before GIA universalized the D-to-Z Color Grading Scale, there was no clear standard to define what diamond color is. A variety of other systems were used loosely, from A, B, and C (used without clear definition), to Arabic (0, 1, 2, 3) and Roman (I, II, III) numbers, to descriptive terms like “gem blue” or “blue white,” which are notorious for misinterpretation. So, the creators of the GIA Color Scale wanted to start fresh, without any association with earlier systems. Thus the GIA scale starts at the letter D. Very few people still cling to other grading systems, and no other system has the clarity and universal acceptance of the GIA scale.
No. Naturally colored diamonds outside the normal color range are called fancy-color diamonds. The FTC provides no guidelines for the use of the term “fancy-color” in the US, but there is general agreement in the international trade about what diamond color range is customary for fancy-color diamonds. These are either yellow or brown diamonds that have more color than a Z master stone or they exhibit a color other than yellow or brown.
The key to understanding a Diamond and its value, it is to understand the 4 attributes that all Diamond shares Color, Clarity, Cut and Carat Weight (known as 4Cs).
The Gemologist Institute of America (GIA), developed the 4Cs in order to create a universal language when it came to the difficult task of determine the Diamond's quality.
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