A-E | F-J | K-O | P-T | U-Z

Facets | Fancy Shape | Feather | Finish | Fluorescence

Girdle | Girdle Thickness | Heart-Shape Cut | HRD

IGI | Inclusion | Invisible Setting


F

Facets: flat planes or surfaces on a diamond. Each facet must be cut in exact geometric relation to the other facets to create the most fire and brilliance.

Fancy Shape: any diamond shape other than round.

Feather: a type of inclusion that occurs naturally in diamonds. Feathers are simply small fractures, shaped like a bird's feather, that touch the stone's surface. Feathers are noted on the diamond’s grading report.

Finish: the qualities imparted to a diamond by the skill of the diamond cutter. The term "finish" covers every aspect of a diamond's appearance that is not a result of the diamond's inherent nature when it comes out of the ground. When a gemologist grades finish, he considers the execution of the diamond's design, the precision of its cutting details, and the quality of its polish. On a diamond's grading report, you will see the diamond’s finish, graded according to two separate categories: polish and symmetry.

Fluorescence: when exposed to ultraviolet light, small percentages of diamonds fluorescence, or emit light. Fluorescence does not necessarily affect a diamond's value; however, it is listed on a diamond grading report as None, Faint, Slight, Medium, Strong or Extreme. Some reports also list the colour of the fluorescence (e.g. blue, yellow, white, etc.). Be aware that stones which give off blue light may actually be more valuable, since the blue light can make them appear "whiter" in daylight or fluorescent lighting.

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G

Girdle: the outermost edge of a diamond that sits in the setting, separating the upper and lower sections of the stone. The girldle varies in thickness, depending on how it was faceted by a cutter during manufacturing.

Girdle Thickness: a diamond's girdle, or outermost edge that separates the upper and lower sections of the stone, varies in thickness depending on how it was faceted by a cutter during manufacturing. If the girdle is too thin, or the stone may chip. If it is too thick, the diamond’s brilliance may be reduced. A properly cut girdle should be even all the way around. If the girdle appears to be a wide band around the diamond, it's probably too thick. If you can hardly see it, it's probably too thin.

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H

Heart-Shape Cut: a type of fancy diamond cut, which is cut to resemble the popular Valentine's Day shape.

HRD: 'De Hoge Raad voor Diamant' is a prestigious independent European gemological certification laboratory based in Antwerp, Belgium that began grading diamonds and providing grading reports in 1976. The HRD does not sell diamonds, but acts as a consultant in the grading of precious gems. It is important to note that a grading report provided by any gemological laboratory is NOT a statement of the monetary value of a particular stone (like an appraisal), but a professional opinion that evaluates only its quality.

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I

IGI: International Gemological Institute. One of the largest, most respected gemological institutions in the world. The IGI is an independent laboratory whose trained gemologists grade diamond quality and provide a grading report along with each stone they grade. The IGI does not sell diamonds, but acts as a consultant in the grading of precious gems, as well as provides educational courses in diamonds and diamond grading. Founded in Antwerp in 1975, the IGI has offices in Antwerp, New York, Bangkok and Mumbai.

Inclusion: a small cloud, feather, crystal or other blemish that occurs naturally inside or on the surface of diamonds. The fewer inclusions, the more rare the diamond and the greater its value. A truly flawless diamond is extremely rare.

Invisible Setting: invisible-set diamonds are placed very closely together, with the metal concealed underneath the diamonds, giving the appearance of a continuous, uninterrupted surface. Since the metal is not seen, this type of setting is an excellent way to showcase the brilliance of the diamonds themselves. It also allows an increased amount of light to enter the stone (and, thus give off more brilliance), since there are no prongs or bezels impeding the light's entry.

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