Also known as fracture filling, a treatment that introduces a glass-like material in the natural feathers or fractures of a diamond or colored gemstone.
For diamonds, this process enhances the appearance of clarity. While the treatment is stable for normal wear, it is not considered permanent. In most cases, should damage to the treatment occur, the diamond can be repaired and its enhancement restored. EGL USA clearly identifies such stones with laser inscriptions, along with special Enhanced Diamond Reports. For diamonds, see also Plotting Diagram.
For colored gemstones — such as alexandrites, emeralds, rubies, and tourmalines — feather filling can also enhance the appearance of clarity. In addition, it can improve durability.
