Carat. Clarity. Color. Cut.
Just like we check for Blue Book value before we buy a car, the 4Cs are a way to compare diamond quality and value. That grade is made up of four factors: carat weight, clarity, color, and cut. Each "C" has its own grading scale for evaluating quality.
When it comes to diamonds, shape refers to the outline of the stone — round, oval, princess, etc. A diamond's cut, on the other hand, refers to the arrangement of a stone's facets. This means a diamond's shapes can be faceted, or cut, in many ways.
Combined, the 4Cs help diamond sellers set prices and compare diamonds, whether you’re shopping for diamond earrings, the perfect tennis bracelet, or your unique engagement ring. The more you understand about diamonds, the savvier you’ll be in choosing yours.
Budgeting with The 4Cs in Mind
As you compare diamonds to work within your budget, consider how you might get a beautiful, sparkling diamond by focusing on the cut while sliding down the scale a few levels on color and clarity. Or opt for a larger diamond but scale back a fraction of a carat to save money. You could also buy a lower-weight diamond but a near-ideal or ideal cut, focusing on the diamond’s radiance and beauty and putting less emphasis on the size.
When you shop for a diamond, you may see a string of letters and numbers that indicate the diamond’s grade. It might look something like this: 1 ct E VS1. Diamond experts will tell you that’s a very nice diamond—and probably an expensive one. Let’s deconstruct this code and learn about how diamonds are graded.
Carat
People often mistake carats as a measurement of size, but they actually measure weight (CTW = Carat Total Weight). As you shop, note that 100 points equal 1 carat.
To shave the cost of a diamond, start by looking at a diamond 10 or 15 points less than a diamond you like, because these tiny increases can really add up.
| Carat Weight | Millimeter (mm) Size |
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0.05 carat | 2.5mm |
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0.25 carat | 4.1mm |
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0.50 carat | 5.2mm |
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0.75 carat | 5.8mm |
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1.0 carat | 6.5mm |
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1.25 carat | 6.9mm |
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1.5 carat | 7.4mm |
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2.0 carat | 8.2mm |
Clarity
A diamond is a thing of nature. Like any rock or mineral, diamonds can have flaws. Choosing a diamond with a difficult-to-detect inclusion or blemish can be a great way to save on cost without sacrificing beauty.
A flawless diamond with little to no imperfections is often desired due to its rarity, but they are also the most costly. But in fact, only about 2% of the world's diamonds are actually flawless. Most are formed with slight imperfections—these are known as inclusions. Inclusions can appear as tiny white points, dark dots, cracks, or scratches. The fewer inclusions, the more valuable the stone.
The GIA Diamond Clarity Grade scale has five main categories of clarity characteristics with 11 grades in all. Most jewelry stores carry VVS as their highest grade. VS or SI are considered by most to be "fine quality" diamonds. Here’s how clarity is measured:
| Grade(s) | Description |
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F | Flawless inside and out |
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IF | Internally flawless — blemishes on the surface but not inside the diamond |
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VVS1, VVS2 | Very, very slightly included |
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VS1, VS2 | Very slightly included |
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SI1, SI2 | Slightly included |
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I1, I2, I3 | Included and detectable with the eye |
Types of Flaws
There are two types of flaws a diamond can have—external and internal. These flaws not only impact value and price, but can also indicate your diamond's vulnerability—heavily included diamonds can be prone to breakage.
When looking at your diamond through a loupe, your Jewelry Consultant will see what is essentially your diamond's fingerprint. These flaws may include:
External Flaws
- Natural: Unpolished surface; the original "skin" of rough diamond
- Cleavage or feather: Inclusion along atomic grain
- Pit: Small indentation on a flat surface
- Fracture: Irregular shaped break
- Cavity: An opening on the surface
- Nick: Minor surface chip
- Scratch: Small groove (can be due to wear and tear)
- Chip: Broken along external edge
- Laser Drill Hole: Clarity enhancements to remove or reduce the appearance of inclusions
Internal Flaws
- Included: Inclusions within diamond
- Carbon spot: Included crystal
- Grain/twinning: Irregularity in crystal
- Pinpoint: Small included crystal (appears white)
- Cloud: Group of pinpoints
- Internal grain line: Visible part of internal grain structure
- Bearded or feathered girdle: Minute to small hairline fracture extending from girdle into stone
Color
Diamonds come out of the earth in many different colors. The market has traditionally valued white diamonds higher than others, and the grading scale offers five groups of 23 letters to reflect that.
| Grade | Description |
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D | Top of the scale — colorless, rarest and most expensive |
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G | Near colorless |
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I | Still appears white, but more affordable |
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J | Human eye begins to detect a yellow tint |
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Z | Unmistakably yellow in color |
Cut
Cut refers to a stone’s shape, facet, and polish. Sometimes diamonds are cut so they’re heavier, thus fetching more value for their carat weight. Sometimes they’re cut to hide or minimize inclusions by expert diamond cutters skilled at bringing the brilliance out of each diamond they work with.
In general, there are three factors that determine a diamond's cut quality:
- Proportion: The relative size and angle of each diamond facet
- Symmetry: The precision of the cut design, especially the facets
- Polish: The smoothness and luster of the diamond's surface
Cut grades are referenced on a diamond's certificate often using the GIA standards of Excellent, Very Good, Good, Fair, and Poor. The quality of a diamond's cut always speaks for itself. The cuts can take shape in a number of ways to work with many types of jewelry and personal preferences:
| Shape Name | Description |
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Asscher | Square shape with cropped corners for an almost octagonal appearance. |
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Cushion | Historical rounded-corner cut that radiates a kaleidoscope of color. |
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Emerald | Wide, flat plane that looks like stairs from the top. Less sparkle, more elongated elegance. |
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Heart | Complex shape with detail best suited to larger-carat diamonds. |
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Marquise | Unique eye-shaped cut that appears larger than it actually is. |
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Oval | Asymmetrical elongated shape with no pointed edges—less likely to snag. |
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Pear | Combines round and marquise characteristics with a tapered shape. |
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Princess | Popular modern cut with pointed corners and lots of brilliance and sparkle. |
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Radiant | Cropped corners surrounding a square or rectangular cut make it extra durable. |
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Round | Most popular cut due to symmetry, sparkle, and timelessness. |