How to Select a Diamond

When it comes to selecting a diamond, there is one rule to follow: remember the four Cs.

Color, clarity, cut and carat weight are the four characteristics that impact a diamond's overall appearance and durability. Knowing the difference between these characteristics can mean the difference between finding an exceptionally brilliant diamond or just a semi-pretty stone.

Diamond Color

While diamonds can come in an array of colors, white diamonds are the diamond against which all other diamonds are judged when it comes to grading a diamond's color.

To judge a diamond's color, the Gemological Institute of America (GIA) developed guidelines based on a lettering system. The letter grade given to a diamond indicates the amount of color in the stone, with the grade of D awarded to rare, totally colorless diamonds. The GIA grading system categorizes a diamond's color as follows:

  • D-E-F: colorless
  • G-H-I-J: nearly colorless
  • K-L-M: faintly tinted, usually yellow in color
  • N-O-P-Q-R: lightly tinted, usually yellow in color; tint can be seen with the naked eye
  • S-T-U-V-W-X-Y-Z: tinted, usually yellow in color but may be closer to brown; tint is visible to naked eye even when the stone is mounted

Another component that impacts a diamond's color is call fluorescence. When a GIA report indicates that a diamond exhibits fluorescence, the diamond's color will change when it is exposed to UV light. A diamond that produces a blue fluorescence will appear whiter or more colorless under UV light, while a diamond that produces a yellow fluorescence will appear even more yellow under some lighting conditions.

Diamond Clarity

A diamond's clarity is graded based on the absence or presence of flaws inside or on the surface of the diamond.

The two types of flaws that can impact a diamond's clarity are inclusions - imperfections inside a diamond such as tiny spots of color or cracks - and blemishes - imperfections on the surface of the diamond, often resulting from the cutting or polishing process.

The GIA grades diamond clarity as follows:

  • FL - Flawless: no internal or external flaws (extremely rare)
  • IF - Internally Flawless: no internal flaws; slight external blemishes
  • VVS1 and VVS2 - Very, Very Slightly Included: minute inclusions; difficult for an experienced grader to detect
  • VS1 and VS2 - Very Slightly Included: minute inclusions; not easily seen by an experienced grader
  • SI1 and SI2 - Slightly Included: inclusions that are noticeable to an experienced grader
  • I1, I2 and I3 - Included: obvious inclusions that can affect transparency and brilliance

It is important to note that if your budget cannot support an FL or even an IF diamond, don't worry - normally, any imperfections in the diamond begin to detract from the stone's beauty only after you reach the I1, I2 or I3 levels.

Diamond Cut

A diamond's cut does not relate to its shape. Instead, it is related to the stone's proportions - its depth and width plus the uniformity of its facets. A poorly cut diamond will lose its sparkle - one of the treasured aspects of diamonds.

When it comes to grading a diamond's depth and width, there are three primary categories: a shallow cut, in which light is lost out of the bottom of the stone; a too deep cut, in which light escapes out of the stone's sides; and an ideal cut, in which light bounces back out of the top generating the diamond's characteristic brilliance.

The uniformity of a diamond's facets, or its symmetry, impacts the diamond's ability to produce scintillation, or its ability to truly sparkle. A diamond's symmetry is graded as either fair or poor.

Diamond Carat Weight

Many might believe that carat stands for a stone's size, but it actually is used to describe a stone's weight, with one carat equaling 200 milligrams of actual weight. With smaller diamonds, the term points might be used, with 100 points equaling one carat.

When pricing a piece of diamond jewelry, the larger the individual diamonds are, the more the piece will cost. For example, a piece with a single one carat diamond will be worth more than a piece with several smaller diamonds that add up to one carat.