Although a diamond may be any color
of the spectrum, grading a cut stone for color means deciding the amount by
which it deviates from the whitest possible. Completely colorless, icy-white
diamonds are rare, and therefore, more valuable. The best way to see the true
color of a diamond is looking at it against white surface.
Although most diamonds are a shade
of white, they do come in all colors - pale yellow, canary, pink, red, green,
blue and brown. These are called "fancies," and they are valued for
their depth of color, just as white diamonds are valued for their lack of
color. The famous Hope Diamond is blue, and the well-known Tiffany Diamond is
- Flawless (FL)
- No inclusions and no blemishes visible under 10x magnification
- Internally Flawless (IF)
- No inclusions visible under 10x magnification.
- Very, Very Slightly Included (VVS1 and VVS2)
- Inclusions so slight they are difficult for a skilled grader to see under 10x magnification.
- Very Slightly Included (VS1 and VS2)
- Inclusions are observed with effort under 10x magnification, but can be characterized as minor.
- Slightly Included (SI1 and SI2)
- Inclusions are noticeable under 10x magnification.
- Included (I1, I2 and I3)
- Inclusions are obvious under 10x magnification which may affect transparency and brilliance.
A diamond's clarity is determined by
taking into account the number, size, placement, color and nature of any
internal "inclusions" or external surface irregularities. Inclusions
are Nature's birthmarks - imperfections such as spots, bubbles or lines -
included in the stone when it was crystallized from carbon millions of years
ago. These marks make each stone unique, for no two diamonds have the same
inclusions in the same places. When inclusions do not interfere materially with
the passage of light through the stone, they do not affect its beauty.
However, the fewer the inclusions,
the more valuable the diamond. Under Federal Trade Commission rules, a diamond
can be called "flawless" only when no imperfections are visible to a
trained eye under x10 power magnification and in good light. Gemological
Institute of America's (GIA) quality analysis system is the most widely used
for grading gemstones in the United States. Clarity is graded according to the
relative position of the diamonds on the Flawless-to-Imperfect scale.
Diamonds are cut according to an
exact mathematical formula. A finished diamond has 58 "facets," which
are the small, flat polished planes cut into a diamond, so that the maximum
amount of light is reflected back to the viewer's eye. This reflection is
called "brilliance," and is extremely important in evaluating the
quality of a diamond. The widest circumference of a diamond is the
Above the girdle are 32 facets plus the
"table," the largest and topmost facet. Below the girdle there are 24
facets plus the "culet," or point. Cut also deals with the shape of
the diamond. Traditional shapes are round, emerald, marquise, pear, oval and
This is the unit of weight used for
diamonds, a word derived from carob seeds used to balance scales in ancient
times. A carat is equal to 200 milligrams and there are 142 carats to an ounce.
Carats are further subdivided into points. There are 100 points to a carat. For
example, a 45-point diamond weighs a little less than half a carat. Because
larger diamonds are quite rare, they have a greater value per carat.