Elegance

The 26 D-Flawless diamonds of various shapes and sizes cut from the Lesotho Promise crystal. Courtesy: Graff

Once upon a time, there was no agreed-upon standard by which diamonds could be evaluated. Traders and jewelers used terms such as river or water to describe diamonds that were the most colorless, and Cape to describe pale yellow diamonds from South Africa’s Cape of Good Hope region. A diamond’s cut was described as “made well” or “made poorly.”

Then in the 1940s, Robert M. Shipley, the founder of GIA, coined the term 4Cs to help his students remember the four factors that characterize a faceted diamond: color, clarity, cut and carat weight. The concept was simple, but revolutionary.

His successor, President Richard T. Liddicoat, expanded his work by developing the now universally-utilized GIA D-to-Z Color Scale and GIA Clarity Scale for diamonds. He also established the scientific methods and procedures for objectively grading a diamond’s quality.

The creation of the Diamond 4Cs and the GIA International Diamond Grading System™ meant two very important things: diamond quality could be communicated in a universal language, and diamond customers could now know exactly what they are purchasing.

Today, the 4Cs of Diamond Quality is the universal method for assessing the quality of any diamond, anywhere in the world. As the creator of the Diamond 4Cs and the International Diamond Grading System™, GIA is trusted by museums, auctions houses, and consumers all over the world to grade nature’s finest treasures.

To understand diamond clarity, we must first understand how diamonds are created. Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called ‘inclusions’ and external characteristics called ‘blemishes.’

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 (FL) No inclusions and no blemishes visible under 10x magnification
• Internally Flawless (IF) No inclusions visible under 10x magnification
• Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
• Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor
• Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
• Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance

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 is 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.

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:

• Brightness: Internal and external white light reflected from a diamond
• Fire: The scattering of white light into all the colors of the rainbow
• Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond

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.’

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.

While now you know what carat means, it’s also important to remember that a diamond’s value is determined using all of the 4Cs, and not just carat weight.