Gletz

Gletz
Dutch or Afrikaans for feather. Also spelt glatts, glatze, gles, and glets.
Global Witness ...

Glets ( or gletz): A word of Dutch origin for a cleavage crack in a diamond that looks like a feather.

Fissure A crack, gletz, feather, possibly reaching to the surface.
Flaw In inclusion or other feature which is visible or reduces clarity in diamonds or other gems.
Flawless Without any inclusions or features adversely affecting clarity.

Cleavage or fracture; may be transparent, but usually has a whitish appearance when seen at right angles to the break. Also called a gletz.
Finish
Quality of a diamond's polish, the condition of its girdle and the precision of the cut.

A feather is a type of inclusion or flaw within a diamond. It is often described as a small crack, fissure or gletz.
Filling ...

See also: Brilliant cut, Rough, Gemstone, Shape, Brilliant