The 4 C’s of Diamonds

The Basics: The 4 C’s

Before hitting the jewelry stores, make sure you do your homework on all things diamonds.

This will assist you in asking the right questions and understanding the many qualities the

salesperson will point out for each stone.

Diamonds are rated on four standards: cut, clarity, carat and color. These standards allow a

buyer to assess the quality of a diamond. However, while carat weight is an objective

measure, all of the other standards are subjective and dependent on the expertise of the

person rating them. Any one diamond’s ratings may vary if assessed by several different



A diamond typically is found in nature as an octahedron-shaped crystal (imagine two four-

sided pyramids with their bases connected). As a result of a diamond’s hardness, it’s very

difficult to change its


Quality cutting is critical to a diamond’s value. A well-cut diamond captures and returns light

through carefully designed, angled planes called facets. Cutting quality is rated on certificates

as excellent, very good, good, fair or poor.

Diamonds come in a variety of shapes. The most common is the round brilliant, which features

58 facets and is generally regarded as the cut that displays a diamond to best effect.

Other popular cuts include the princess and the emerald. The princess has a square face that

tapers down to a triangular shape. The emerald is a rectangular shape.

Other shapes include the oval, cushion, marquise and a variety of specialized designer cuts.

When a gem cutter looks at a rough diamond, he will decide the best shape to highlight the

diamond’s assets or hide its flaws. The more facets a cut has, the better suited it is to hide



Gemstones were once graded based on their “water,” or apparent transparency. With modern

equipment, stones can be closely examined under bright lights and high magnifications.

Stones with great clarity have two major benefits: They are more attractive due to their


ability to capture light, and they are structurally sound. Flaws in diamonds are called

inclusions (internal) and blemishes (external).

For instance, a diamond could be internally flawless having no inclusions, but it may have a

blemish in the form of a scratch, chip or tiny pit on its surface. Or it could have a fabulous cut

and polish that help to hide a small inclusion. Inclusions can be bubbles, tiny bits of coal or

small fractures.

Like all natural gemstones, diamonds are not created under controlled laboratory conditions.

Some see their tiny flaws as proof of their organic nature and a part of their charm. The

Gemological Institute of America, considered the accepted authority on gems in the United

States, created the accepted standard definitions for levels of clarity.


A colorless diamond reflects light back in a pure rainbow without adding any other colors to

dilute this effect. The GIA rates the colors of diamonds from D to Z. Diamonds rated D to G

are considered essentially colorless. Diamonds rated H and I are considered near colorless.

Diamonds rated J to Z have increasing yellow tones.

Carat Weight

One carat equals 0.007054 ounce. A one-carat diamond cut in a round shape would be about

6.5mm in diameter, or one-fourth of an inch.

TIP As a general guide, look for a diamond that is at least one-third of a carat, has a clarity rating

of SI or better, is in the colorless or near colorless range (D to I), and has a cut rating of good

or better.


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