Are Flawless Diamonds Perfect?

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HomeDiamond AdviceAre Flawless Diamonds Perfect?

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To most people, the word "flawless" means perfect. When it comes to diamonds, however, it's a bit more nuanced. Internally Flawless diamonds are incredibly rare-less than 0.5% of diamonds fall into this category. So what about the rest of the diamonds? Rest assured: there are plenty of beautiful diamonds out there and more than one will fit your definition of "perfect."

What Are Inclusions?

A diamond is considered to be Internally Flawless if it contains no inclusions. Inclusions are tiny imperfections that form inside a diamond as it grows. Inclusions are features like liquid or gas bubbles, small cracks, or other mineral grains.

This is an example of a diamond rated I3 which has several black spots, clear scratches, and small bubbles.
The inclusions in this diamond are a small cluster of mineral grains in the center, highlighted by the green box. This diamond is an SI2. From Brian Gavin Diamonds.
diamond inclusion chart

What causes inclusions and why are flawless diamonds so rare? First, let's review how diamonds form. Diamonds are made of carbon and form deep within the Earth-about 90 to 125 miles below the Earth's surface. Imagine the weight of a hundred miles of rock-this means the temperature and pressure are both really high. This is exactly what diamonds need to form.

These conditions are usually found deep below old, stable continental crust. The rocks at these locations contain carbon and the intense pressure causes the carbon atoms to link each other. Carbon atoms form really tight links-also known as bonds-and as the atoms bond, they develop into a crystal. Any other carbon atoms that are nearby will latch onto this crystal. The crystal will grow larger and larger, eventually forming a diamond.

However, the process is not always neat and tidy. All kinds of foreign material can get into the diamond: water, gas, pieces of other minerals. Also, since the diamond is under such high pressure, cracks can form while the diamond is growing. These little flaws are what gemologists call inclusions.

Inclusions can affect diamonds in two ways. Clarity, a measure of how easily light can pass through a stone, is determined by the number and type of inclusions in a diamond. A diamond with lots of inclusions, or large inclusions, will have a lower clarity grade. Inclusions block light from passing through the diamond, causing it to lose some of its sparkle. In fact, some diamonds are so heavily included that they appear to be gray or black.

Inclusions also impact a diamond's structural integrity. Diamonds are the hardest mineral, which means they won't get scratched, but too many inclusions can make a diamond brittle. If a diamond with a crack or air bubble gets hit in the wrong spot, it can crack. Fortunately, this is rare and only happens when diamonds are very heavily included.

Flawless or Included-How Do You Choose?

A close up of a flawless diamond-this is the textbook definition of perfect. From Blue Nile.

Inclusions are present in almost every diamond. While it may seem like flawless diamonds are the best, the reality is that most inclusions are so small that you'll never be able to see them. A diamond's clarity will tell you everything you need to know about its inclusions.

Diamond clarity is divided into the following grades:

No Inclusions:

  • Flawless (F)
  • Internally Flawless (IF)
From James Allen.

Flawless and Internally Flawless diamonds are rare and very expensive. Flawless diamonds have no inclusions and no blemishes on the surface. Internally Flawless diamonds have no inclusions, but can have small blemishes on the surface, which can be polished away. Sure, these diamonds fit the textbook definition of perfect, but their high cost makes them impractical.

Minute Inclusions:

  • Very, Very Slightly included 1 (VVS1)
  • Very, Very Slightly included 2 (VVS2)
From James Allen.

As their name suggests, diamonds in this grade have very few inclusions. The inclusions that are present are tiny-so small that they can only be seen under a microscope. The average person likely won't be able to tell the difference between a VVS diamond and an F or IF diamond. Still, these diamonds come at a high cost.

Minor Inclusions:

  • Very Slightly included 1 (VS1)
  • Very Slightly included 2 (VS2)
From James Allen

Although VS diamonds have more inclusions than VVS diamonds, these inclusions are so small that they don't interfere with clarity too much. Inclusions at this grade are still invisible to the naked eye.

Noticeable Inclusions:

  • Slightly Included 1 (SI1)
  • Slightly Included 2 (SI2)
From James Allen.

Diamonds at this grade have larger inclusions. Some inclusions may be visible to the naked eye and they are large enough that clarity is affected. SI diamonds may appear cloudy or less sparkly than VS, VVS, IF, and F diamonds. This grade is where prices begin to drop.

Obvious Inclusions:

  • Included 1 (I1)
  • Included 2 (I2)
  • Included 3 (I3)
From James Allen

I grade diamonds are heavily included and aren't a great purchase. Inclusions are visible to the naked eye and are often large cracks or surface blemishes. In addition to being visibly flawed, these diamonds are also brittle and could potentially crack.

So how do you choose the perfect diamond? Like everything, it's a matter of getting the best diamond for your budget. The goal isn't to get a flawless diamond, but one that is eye clean. An eye clean diamond has no visible flaws. An eye clean diamond may have some tiny inclusions, but these are only visible with a microscope or a jeweler's loupe-not to the naked eye.

You can find eye clean diamonds in the F, IF, VVS, and VS grades. This rule isn't set in stone-some SI diamonds can be eye clean-but it's a good place to start.

Compare these two diamonds from Blue Nile. Both are 1 carat, ideal cut, E color round diamonds. The diamond on the left is FL and the diamond on the right is VVS1. To the naked eye, it's nearly impossible to tell the difference.
Look at this 1 carat, F color, ideal cut round diamond from Blue Nile. It is graded VS1 and has a few inclusions that are barely visible in this HD photo.
The diamond on the left is VVS1 and the diamond on the right is IF. Both display a beautiful sparkle and no visible inclusions. With a price difference of $1,500, it's worth considering a lower clarity grade!

Other factors to consider are diamond size and shape. Generally, the larger the diamond, the more its flaws will show. For diamonds larger than one carat, it's best to stick with VS2 or better.

Also, certain diamond shapes hide inclusions better than others. Brilliant cut shapes like round, oval, pear, princess, marquise, and radiant have a cone-like shape, so small inclusions aren't as apparent. For many of these cuts, you can find SI diamonds that are eye clean. Step cut diamonds like emerald and Asscher shapes are rectangular, so inclusions will be more obvious.

Shape and cut matter. Compare these two emerald cut diamonds from Blue Nile. Both are 1 carat, G color, and VS1 clarity. The diamond on the left has a good cut and a small inclusion is visible in the center of the stone. The diamond on the right has a very good cut but no inclusions are visible.

Evaluating Clarity Online

Set in platinum,  it's impossible to see any flaws in this 1 carat, ideal cut VS1 diamond. From James Allen
Find this Ring
at James Allen

Shopping for diamonds online is a breeze now, thanks to retailers like James Allen and Blue Nile. Both websites offer videos and high-resolution photos of their diamonds, as well as the lab report for each diamond.

If you know what color, cut, and shape you want, search their diamond inventories and look at all the different clarity grades. Zoom in on the photos and look at the diamonds in 360°. Remember that these images are highly magnified and that the clarity grade is a good indicator of whether you'll be able to see the flaws with the naked eye.

Every diamond is unique. With some research and education, you can find a diamond that fits your definition of perfect-whether it's flawless or not!

Courtney Beck Antolik

Courtney Beck Antolik is a geologist and science writer based in Denver, CO. She received a B.S. (2010) in Geology from Texas A&M University and an M.S. (2013) in Geological Sciences from the University of North Carolina at Chapel Hill. Courtney’s experience with minerals includes a zircon geochronology project and a semester teaching mineralogy labs. Her favorite mineral is beryl, but diamond is a close second.

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