• Faceted Girdle

    Describes the girdle of a diamond that has been polished with a series of tiny steps or facets  around the circumference or perimeter.

  • Facets

    Any one of the flat, polished surfaces on a diamond.

    1 Table

    2 Bezel facets

    3 Star Facets

    4 Upper-Girdle Facet

    5 Lower-Girdle Facets

    6 Pavilion Main Facets

  • Fancy Colour

    Any positive diamond colour other than white, brown, or grey with a significant level of saturation. Natural fancy colour in diamonds is rare and valuable; the colour is caused by either impurities or structural abnormalities. Three factors to consider when grading a coloured diamond are body colour, tone, and saturation. Examples of fancy colours, or ‘fancies’: yellow diamonds, orange diamonds, pink diamonds, red diamonds, blue diamonds, purple diamonds, and green diamonds. Examples of non-fancy colours are grey and brown.

  • Fancy Shape

    Diamond cut into any shape other than a round brilliant cut. Some examples of fancy shape diamonds are: princess cut, emerald cut, oval cut, marquise cut, heart cut, pear cut, and asscher cut diamonds.

  • Feathers

    Type of cleavage inclusion in a diamond with a wispy, feather-like appearance; the feather-like part extends from the origin of the break. Feathers occur along a cleavage plane, or plane of weakness, in a diamond due to directional hardness; they may appear transparent if viewed head on, or bright white if viewed at a 90° angle.

  • Finish

    Qualitative description of the make of a diamond in terms of polish and symmetry.

  • Fire

    Visible play of colours created by the break-up of light in a diamond. When light enters a diamond, it reflects off of the pavilion facets and refracts, or bends, into a rainbow of colours as it leaves the crown facets. Also known as dispersion.

  • Fish Eye

    Unattractive donut-shaped white ring seen under the table of a round brilliant cut diamond with too shallow a pavilion depth. The ring is caused by the reflection of the diamond’s girdle. Diamonds with a fisheye lack brilliance, and show little life.

  • Flash Effect

    Bright, vivid streak of colour found in the glass-like resin filling of diamonds treated by fracture filling.

  • Flat Diamond

    Trade term used to describe a diamond with a very shallow crown height and/ or pavilion depth. Flat round brilliant cut diamonds with a shallow pavilion tend to show a fish eye. Flat diamonds lack some brilliance and life.

  • Flawless

    Refers to the clarity of a diamond with no inclusions or blemishes. Flawless diamonds are exceptionally rare.

  • Fluorescence

    Natural characteristic which causes many diamonds to glow under ultra violet light (UV), which is abundant in natural daylight and some artificial lighting. Fluorescence is caused by sub-microscopic structures within the diamond. Diamonds can have various colours of fluorescence, with blue being the most common.

  • Four C’s

    Four fundamental criteria on which the quality and value of a diamond are judged: cut, colour, clarity, and carat weight. Two additional factors, transparency and the confidence in a diamond grading certificate are also important value factors. Click here to learn more about the C’s of diamond grading.

  • Fracture

    Type of break or crack inclusion in a diamond that is irregular, jagged and splintery. A fracture may not follow along a cleavage plane as does a feather, but spreads across the diamond in any other direction.

  • Fracture Filling

    Treatment to enhance the apparent clarity of a diamond, whereby a glass-like resin is injected into feathers or fractures that reach the surface of the diamond. Feathers are visible when light reflects off of them; by filling them with a resin, light is able to travel through the feather, making it less visible. The resin causes what is known as a flash effect in the treated diamond. Fracture filling is not a stable diamond treatment and is easily altered with heat; click here to learn more.