Groupon GUIDE

Diamond Buying Guide

BY: GROUPON EDITORS | 8.9.2016 |

While shopping for diamonds, it might seem impossible to tell the difference between two stones even with a microscope-enhanced view. And while the variances in the diamond qualities of two stones might seem miniscule—and often, they can be—they also can make a big difference in what you end up paying. Luckily, the essential characteristics that affect the value and appearance of a diamond are pretty straightforward. They're known as The Five Cs: cut, color, clarity, carat weight, and certification. Read our diamond buying guide to learn more about each.

Diamond Cut

What it is: A grade that measures the diamond's reflective qualities, or what consumers generally perceive as brilliance

How you'll notice it: If light returns out of the diamond's top, that means it's cut with correct proportions. If light escapes through the bottom or sides, that means it's cut too shallow or deep.


Reflects nearly all of the light that enters the diamond. A rare cut that results in exquisite brilliance and sparkle.

Very Good

Reflects most all of the light that enters the diamond, resulting in superior brilliance and sparkle.


Reflects a large amount of light that enters the diamond, resulting in average brilliance and sparkle.


Cut allows only some of the light to escape out of the sides or the bottom, resulting in reduced perception of brilliance.


Cut is deep and narrow or shallow and wide, resulting in most of the light escaping out of the sides or the bottom. Appearance of the stone may seem dull.

Pro Tip: Diamond cut isn't the same as diamond shape. The term shape refers to the diamond's outward appearance (e.g., princess, round, or pear).

Diamond Color

What it is: Refers to a diamond's lack of color, with grades signifying the whiteness of a diamond

How you'll notice it: Probably the easiest of the diamond qualities to quickly assess, color is usually spotted in faint yellows in the stone.




Nearly colorless


White in color


Somewhat noticeable very faint yellow in color


Noticeable faint yellow in color


Noticeable light yellow in color

Diamond Clarity

What it is: A measure of the size, number, and position of a diamond's tiny imperfections, AKA "inclusions"

How you'll notice it: Realistically, the only way to actually see the level of a diamond's clarity is with a microscope. Most inclusions are so tiny that they don't make much—or any—difference on how it looks on sight.

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-VVS2)

Inclusions so slight they are difficult for a skilled grader to see under 10x magnification

Very Slightly Included (VS1-VS2)

Inclusions are observed with effort under 10x magnification, but can be characterized as minor

Slightly Included (SI1-SI2)

Inclusions are noticeable under 10x magnification

Included (I1, I2, I3)

Inclusions are obvious under 10x magnification, which may affect transparency and brilliance

Diamond Carat Weight

What it is: Put simply, the weight of a diamond—one carat equals 0.2 grams. Each carat is divided into 100 points and corresponds to 0.2 grams. So a diamond with 50 points, for example, would equate to a ½-carat stone.

How you'll notice it: Generally, the bigger the diamond, the higher the carat count. However, the cut of a stone can also affect how big it appears to be, so don't assume the largest diamonds will always have the highest carat counts.

Diamond weight is typically measured in carats. The carat weight listed in the product description is approximate and may vary up to 0.05 carats.

1/10 0.09‐0.11 1 1/4 1.2-1.35
1/8 0.12‐0.14 1 1/3 1.36-1.44
1/6 0.15‐0.17 1 1/2 1.45-1.57
1/5 0.18-0.22 1 5/8 1.58-1.69
1/4 0.23-0.29 1 3/4 1.7-1.82
1/3 0.3-0.36 1 7/8 1.83-1.94
3/8 0.37-0.44 2 1.95-2.15
1/2 0.45-0.57 2 1/4 2.2-2.35
5/8 0.58-0.69 2 1/3 2.36-2.44
3/4 0.7-0.79 2 1/2 2.45-2.57
7/8 0.8-0.94 2 3/4 2.7-2.82
1 0.95-1.1 3 2.95-3.1

Pro Tip: The most common engagement-ring sizes are ½ carat, 1 carat, and 2 carats.

Diamond Certification

What it is: A comprehensive report for a diamond that details its weight, cut, and overall quality, and gives buyers confidence by serving as proof of the diamond's quality.

How you'll notice it: This one's easy! It'll be included with your piece of jewelry.

Pro Tip: Reputable grading laboratories that provide reports and documentation include GSI, GIA, IGL, IGI, and AGSL.

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BY: Groupon Editors