A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0-9

F Edit 23 terms found

F
A grade in GIA’s Color Grading System…. at the end of the “Colorless” category.
Face Up Position
When you view the top of a diamond, perpendicular to the table.
Facet
The smooth, flat faces that are polished on the surface of a diamond. They allow light to both enter a diamond and reflect off its surface at different angle. The way light interacts with these facets affects a diamond’s brilliance and sparkle. A Round Brilliant Cut diamond has 58 facets (or 57 if there is no culet). The shape, quantity, and arrangement of these facets will differ slightly among other fancy shapes.
Faceted Girdle
Sometimes diamond cutters will place facets on the girdle to eliminate noticeable breading, roughness, or to help camouflage a thick girdle.
Fancy Cut
Sometimes used to refer to a gemstone cut in any shape other than the standard round cut, but also used to refer to gemstones that are cut in a shape other than the well known shapes of round, oval, pear, trillion, marquise, etc.
Fancy Diamond or Fancy Color Diamond
Any diamond with a natural body color strong enough to be attractive, rather than “off color”. A body color of light yellow or light brown would need to be beyond the “Z” color grade to be considered a Fancy Color.
Fancy Shape Diamond
Any diamond cut into a shape other than round. Fancy cuts include the Marquise Cut, Asscher, Emerald Cut, Heart Shape, Pear Shape, Keystone, Half Moon, Kite, Triangle, and many others. I’ve even seen them cut into the shape of Christmas Trees, Horse Heads, Tennis Rackets, etc.
Feathers
These are small fractures in a diamond. In some cases the feather both begins and ends within the diamond’s surface and, in other cases, the feather begins inside the diamond and extends to the surface. The term “feather” comes from the fact that, under magnification, these fractures often seem to have an indistinct, feathery shape to them. While the idea of buying a diamond with “fractures” or “cracks” may sound scary, the reality is that, with normal wear and care, most feathers pose no risk to the diamond’s stability. Most diamonds with feathers have survived their growth and their journey to the surface intact… once on the surface, they also survived the mining process, as well as the brutal stresses of the diamond cutting process. Though diamonds are certainly not invulnerable to damage, basic consideration to their care and handling during everyday wear will most likely protect them over the course of several human lifetimes.
Finish
This refers to the quality of how the diamond cutter executed the designing, fashioning, and faceting the diamond. If you look at a diamond’s grading report, you will see its finish graded according to two separate categories: polish and symmetry
Fire
The rainbow or colors that light rays form as they move through a gemstone. This is another word for “dispersion”.
Fisheye
A diamond whose pavilion is exceedingly shallow, producing a glassy appearance (a noticeable lack of brilliancy) and the reflection of the girdle that starts to come into view in the table area.
Fissure
A surface crack on a gemstone. Gems with fissures may be Fracture Filled.
Flat Stone
A Round Brilliant Cut diamond with a very thin crown and pavilion.
Flawless (FL)
No blemishes or inclusions when examined by a skilled grader under 10X magnification.
Flip Lock Clasp
Clasp used on special Oyster bracelets, whereas the buckle utilizes a “flip-lock” safety clasp to help prevent accidental loss. These are often found on divers’ models (i.e. Submariner, Sea-Dweller).
Fluorescence
The ability of some gems to appear a different color when viewed under ultraviolet light. If or not a stone has fluorescence is a valuable aid in gem identification.
Foilback
A faceted glass or quartz stone which has a pavilion that is coated with a silver colored paint to reflect light and act like a mirror. It is commonly seen in costume jewelry. Before, modern, highly reflective cuts were developed, even diamonds were foilbacked.
Four C’s
A phrase used to describe the 4 characteristics used to determine a diamond’s value. All the characteristics start with the letter “C”: Cut, Color, Clarity, and Carat weight.
Fracture
An internal or external break or crack in a diamond that is not in the direction of a cleavage plane. Irregular in shape, they usually appear step-like or as a splinter. An internal fracture is also called a feather… a much nicer term to say that you have a feather in your diamond verses having a crack in your diamond!
Fracture Filling or Fracture Filled Diamond
A diamond enhancement process in which a fracture in a diamond is filled with an artificial substance. The fracture that is filled normally reaches the surface of the diamond or it could be laser drilled and then filled. A Diamond Grading Report cannot be issued for a diamond of this type because its clarity characteristics are not considered permanent.
Full Cut
A round-shaped, brilliant-cut gemstone.
Full Cut Diamond
A description of a Round Brilliant Cut diamond with 57 or 58 facets. Consisting of 32 crown facets and a table facet above the girdle and 24 pavilion facets and possibly a culet facet below the girdle.
Fuzzy Girdle
Also called a Bearded Girdle. If a diamond is “rounded up” too quickly in the bruting process, the surface of the girdle will lack the smoothness and waxy luster of a finely turned girdle. As a result, numerous minute, hairline fractures that extend a short distance into the stone. The girdle can be polishing of faceted to remove or minimize the fractures.