It’s not easy being a diamond. After forming deep within the earth under tremendous heat and pressure and then riding a volcano of molten rock 100 miles up to the earth’s surface, you are going to show your age. Especially when your age is a billion years or so.

Only the hardest substance on earth could finish this geologic odyssey so transparent, brilliant and beautiful. Still, if you look closely enough using a microscope, every diamond has tiny signs of its journey. These microscopic characteristics are unique for each diamond, like a fingerprint.

Diamonds that have no inclusions visible under 10x magnification are so rare that it’s likely many jewelers have never seen one. These diamonds are at the top of the diamond clarity grading scale developed by the Gemological Institute of America, still the leading diamond grading laboratory in the world today.

Diamond clarity is graded under standard viewing conditions with 10x magnification. The grader carefully examines the diamond in order to identify internal clarity and surface characteristics. A minimum of two graders assigns their impression of the diamond’s clarity.

Tiny crystals and other features enclosed in the diamond when it formed are called inclusions. Surface features that remain on the outside of the gem after polishing are called blemishes.

Diamonds with no internal inclusions visible at 10x magnification are IF diamonds: diamonds that receive the Internally Flawless clarity grade on their GIA diamond grading report. Diamonds that have no inclusions or surface blemishes visible under 10X magnification are Flawless, or FL clarity diamonds.

So what are the differences between FL and IF diamonds? Flawless and Internally Flawless diamonds have the same internal clarity. The difference between a Flawless diamond engagement ring and an Internally Flawless diamond engagement ring is the presence of blemishes on the diamond's surface that can be seen by a professional grader using 10x magnification.

The tiny features on the surface of a diamond, that separate an IF diamond from a Flawless diamond fall in different categories.

The most common surface feature flagged by the diamond grader is surface graining. Graining is an area of irregular crystal growth, a sign that conditions changed when a diamond was forming. When the graining appears on the surface, it often can’t be removed by polishing.

Another kind of surface feature that graders can see under magnification is called a natural, an unpolished area of the outside or skin of the diamond crystal left unpolished, often because removing it might leave a small cavity.

Decisions made by the diamond cutter like a tiny extra facet or marks from the polishing of the diamond visible under magnification can also result in a Internally Flawless diamond instead of a Flawless diamond.

You won’t usually the surface features that make the difference between a Flawless and IF diamond marked on the clarity plot on the GIA grading report. In this case they will be mentioned in the notes section.

It is nearly impossible for the naked eye to see the difference between Flawless and Internally Flawless diamonds, especially when they are set in engagement rings.

Even trained gemologists using magnifications may have a difficult time. But the fact that it’s difficult to tell the difference between Flawless and Internally Flawless diamonds doesn’t mean that they are priced almost the same.

Like the rest of the 4Cs, clarity’s influence on value is based on rarity. Diamonds graded Flawless are very rare and therefore very valuable. IF clarity diamonds are also very rare and valuable, but a bit less so.

Is it worth it to pay for a Flawless or Internally Flawless diamond? We don’t think investing in details that don’t make a difference to your diamond’s beauty is worth compromising other factors like cut quality or carat weight. Buying a diamond that has a lower quality grade but still no eye-visible inclusions will leave more money in your budget to buy a larger, more beautifully cut diamond.