Buying the right diamond

Buying the Right Diamond

A Guide to the Four Cs

For most people, the purchase of a diamond engagement ring is baffling, to say the least. It’s especially daunting because it is likely to be among the most costly acquisitions a couple makes. Most people have no idea how to determine the value of a ring and its diamond. What should you look for? What’s important?

You might have heard of the “Four Cs” that are attributes that define every diamond. They are: Carat, Clarity, Color, and Cut. The last attribute, “Cut,” has two distinct meanings: the shape of the diamond and the quality of its cuts. “Quality” is what the “Cut” of the 4Cs refers to and will be discussed later in this brochure. First, we’ll discuss a diamond’s shape.
The Round Brilliant shape is by far the most popular; in fact, it has been the top-selling diamond shape for more than one hundred years. The round brilliant most effectively displays a diamond’s unique ability to reflect light and to sparkle. (The oval and pear-shaped cuts are variations of the round brilliant.) When cutting Round Brilliant diamonds, the cutter must adhere to a set of strict guidelines that will maximize the diamond’s brilliance. (Notice that the facets on Brilliant diamonds are triangular or kite-shaped.)
Diamond shapes



CUT — In grading, “cut” evaluates the skill in the cutting of the diamond. Cut is arguably the most important element because it is directly responsible for the diamond’s sparkle and brilliance.

A well-cut diamond is cut precisely to the proportions that yield the most light return. Here’s the reason a diamond sparkles: Light enters through its table (top) and reflects off the cone-shaped pavilion until it comes back through the top, giving the stone that spectral sparkle. But if a diamond isn’t cut well, the light never comes back up; it leaks out the bottom or sides of the stone. It has little sparkle and life.

Three components comprise “cut.” They are: proportions, symmetry, and polish. Do the cuts on the diamond meet the angle guidelines for maximum dispersion of light? Is the stone symmetrical? Are the stone’s surfaces smooth? Can you see sanding marks? All three of these elements greatly affect the quality of the cut and the diamond’s value, brilliance, and beauty. A grade is assigned to the Cut.

Light Path Entering and Leaving a Diamond

Light Path


Diamond shape

All other shapes of diamonds are referred to as “fancy” cuts, and there are many. Among rectangular stones, the brilliance of the round standard is rivaled only by the square princess cut and its cropped-cornered cousin, the radiant cut. The emerald cut is elegant and always popular and is an example of a “step-cut” diamond. (Notice that its facets are rectangular shaped – like steps.)


CLARITY — Clarity is the evaluation of a diamond’s internal and external characteristics. The fewer inclusions or blemishes, the more desirable the diamond. (Inclusions are inside the diamond; blemishes are on the outside of the diamond.) To locate most of these tiny characteristics, a jeweler will use a ten power microscope, then, evaluating the size, location, nature, number, and color of all the inclusions and blemishes, a clarity grade is assigned. This characteristic is more than cosmetic; a heavily included diamond can be susceptible to breakage.

There are six main categories:
  • Flawless (FL) — Extremely rare. No inclusions or blemishes.
  • Internally Flawless (IF) — No inclusions and only minor blemishes.
  • Very Very Slightly Included (VVS) — Very minute inclusions seen under scope.
  • Very Slightly Included (VS) — Minor inclusions seen under scope.
  • Slightly Included (SI) — Noticeable inclusions seen under scope and a small percentage visible to the naked eye.
  • Included — Significant inclusions seen with the naked eye
Notice that inclusions are visible to the naked eye only in the I grade. In most cases, there’s no link between clarity and beauty.


Colorless to Light Yellow


COLOR — Color for white diamonds can vary from colorless (“D” grade and exceedingly rare) to light yellow (“Z” ). Most diamonds possess some degree of yellow or brown. Small, nearly undetectable, differences in color can make a substantial difference in a diamond’s cost.

Generally, the more colorless the diamond the greater its value. If a diamond is well cut, and this is especially true with the round brilliant cut, the diamond’s refraction and dispersion often will disguise certain degrees of coloration.

A stone with a color rating near the bottom of the alphabet may benefit from a yellow gold setting instead of a platinum or a white gold setting. Stones that possess more color than a “Z” rating may be prized as a Fancy (Yellow or Brown or Red or Blue, etc.).



CARAT — This is the easiest of the 4Cs to determine: The loose diamond is weighed on a calibrated scale. (A carat equals 1/5 of a gram or 1/142 of an ounce.) Each carat is divided into points; each point represents 1/100th of a carat. So, a “half carat stone” contains fifty points.

As diamonds increase in size, their cost tends to increase geometrically. Thus, a one-carat diamond will cost considerably more than twice as much as a one-half carat stone of equal quality. But carat weight can be very misleading. For example, a diamond might have far greater brilliance and more value if more of it were cut away, and it consequently weighed less. Diamonds of equal carat weights can have huge disparities in price.

Some diamond shapes, like the cushion cut, do not really lend themselves to small stones, whereas even a small round brilliant stone can be very striking. You can decide what diamond size will work best for you and your budget by balancing carat weight against the other characteristics.