F-J | K-O
Shape | Feather
Thickness | Heart-Shape
Cut | HRD
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.
Shape: any diamond shape other than round.
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 diamonds grading
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 diamonds finish, graded according
to two separate categories: polish and symmetry.
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 color 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.
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.
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 diamonds
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.
Cut: a type of fancy diamond cut, which is cut to resemble
the popular Valentine's Day shape.
'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.
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.
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.
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.
More on diamonds:
F-J | K-O