Facets There are tiny surfaces polished onto a rough diamond that give a finished diamond its shape. The way light interacts with these facets affects a diamond's brilliance and sparkle.

Fancy Shapes Any diamond shape other than round - e.g. marquise, square, emerald, oval, heart and pear.

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

Finish The word finish is used to describe the exterior of the diamond. If a diamond is well polished, it has a very good finish. Fire Often a term used instead of "dispersion," it is the variety and intensity of rainbow colors seen when light is reflected from a diamond. Flat-top Setting Like the Gypsy setting, this setting has a band that is one continuous piece that gets thicker at the top. A flat-top setting grows broader at the top so that a faceted stone can be inserted into the ring at the broadest part. The stone is held in place by metal clips attached at the stone's girdle.

Fluorescence When exposed to ultraviolet light a diamond may exhibit a more whitish, yellowish or bluish tint, which may imply that the diamond has a property called fluorescence. The untrained eye can rarely see the effects of fluorescence. Diamond grading reports often state whether a diamond has fluorescent properties. Fluorescence is not considered a grading factor, only a characteristic of that particular diamond.