When speaking of diamonds, the “F” word can mean Fracture, Fissure or Feather. These terms all describe naturally occurring characteristics within a diamond that affect its clarity.
Fractures are breaks in diamonds that are not parallel to the cleavage plane. Fractures are usually irregular in shape, making a diamond look chipped.
Fissure or Cleavages are cracks in a diamond that occur in a straight line. If the cracks reach the surface or run deep, the durability of the stone may be reduced with the possibility of the diamond breaking with age.

Feathers are cracks in the stone that resemble the design of feathers. The presence of feathers in a diamond usually does not affect the life of the stone unless and until the feather runs through a major length of the stone or shows major stress points where it can break.
Fractures, fissures and feathers cannot be polished out to enhance a stone, but they CAN be filled with a type of liquid glass containing lead (Pb). This process is somewhat like filling a crack in a car windshield.

The imperfection is still there but it is just less visible to the naked eye. This “fracture filling” is known as “clarity enhancement” or “CE.” It makes a less perfect stone look better to the eye.
Filling these fractures does not strengthen the stone. In fact, if subjected to heat and pressure – such as when the diamond is reset, resized or cleaned – the stone can become damaged and even break. Even a slight tap in an unfortunate spot can ruin a treated diamond.
What does “CE” do to pricing and value?
“Clarity enhanced” or “fracture filled” diamonds should carry a lower price. They will still sparkle, but they are certainly less valuable and should be priced accordingly.
If you want to achieve the sparkle of a large diamond with high clarity, but the one you really want is beyond your budget, a fracture filled or ‘CE’ clarity enhanced diamond may be just the thing for you. Be aware though that such a diamond does not have the rarity or the intrinsic beauty of an untreated diamond and your price should reflect this.
A Fraudulent Practice?
Not necessarily. “Fracture filling” only becomes unethical when clarity enhancement is intentionally concealed and not disclosed at the point of sale.
Should the Jeweler Disclose Enhancements?
FTC Guidelines for the Jewelry Industry strongly state that “it is illegal for a Diamond Seller NOT to Disclose that a diamond has been Clarity-Enhanced by fracture-filling.
Customers should ask for a diamond grading report and verify that they understand exactly what they are paying for. Each term used in describing a diamond on the grading report should be discussed at the point of purchase. A knowledgeable and trusted independent jewelry appraiser is needed when making important purchases.
What should I do?
When you are unsure, it’s a good idea to seek the advice of a third party independent jewelry appraiser who is also a gemologist. If you have a concern about a recent diamond purchase, bring it in to the Jewelry Judge as soon as possible.
For the informed consumer, there is no reason to fear the “F” words. We are here to help you enjoy a fantastic and fun experience with your fascinating diamond purchase.
Note: A diamond grading report is not a guarantee of value, merely a description of the unique features of a specific diamond based upon laboratory examination – but that’s the subject of another article!