As with any precious stone, when jewelers are grading diamonds they are grading the “4 C´s” – Color, cut, carat, clarity – into account in order to determine value. However, of these four characteristics, it is generally accepted that cut has the greatest impact on a diamond’s overall appearance.
When it comes to color, jewelers grades diamonds on a scale from D (no hue) to Z (a yellowish hued stone). The less color a diamond has, the more value it has. However, we note that some diamonds with a yellow or brown tinge are actually quite beautiful. And thus they may be valued highly despite being lower on the color scale.
Cut is arguably the most important factor in grading a beauty of diamonds. A well-cut diamond will exhibit brilliance (the amount of white light reflected back to the viewer). These diamonds will also exhibit fire (the dispersion of light into the colors of the rainbow), and scintillation (the “sparkle” of the diamond as you move it). A poorly cut diamond, on the other hand, will appear dull and lifeless.
Measurement of a weight of a diamond is carat. One carat is equal to 200 milligrams. The more carats a diamond weighs, the more valuable it will be. This is very important in grading diamonds. However, two diamonds of equal carat weight can have very different values depending on the other “C´s.” For an example, a one carat diamond with poor clarity and color will be worth far less than a one carat diamond with excellent clarity and color.
Finally, jewelers grade diamonds for clarity on a 6 point scale. From flawless (no inclusions or blemishes visible to the naked eye) to included (visible inclusions or blemishes). Again, the more flawless a diamond is, the more valuable it will be.
Keep in mind that these are only general guidelines. When determining the value of a diamond, a trained professional will take all of the above factors into account, as well as any unique characteristics that might impact the stone’s desirability. If you wish to read about value of diamond rings, enter here.