matter that becomes clear ceases to concern us," said
Nietzsche. While the renowned philosopher was probably
not referring to diamonds with that observation, his point
was well taken. When a diamond's clarity is assured, all
of the other three Cs fall into place.
What exactly is clarity and why is it so important, you
may well ask? Technically, a diamond's sparkle comes from
its ability to reflect and refract light. How the diamond
achieves this is both magical and scientific, dependent
on both the natural characteristics of the stone and the
effectiveness of its cut.
Light it Up
It all begins when a beam of light touches the surface
of a diamond and part of the ray is reflected back to
the viewer. As the rest of the ray penetrates the stone,
it is refracted or bent, by the stone's density, reflected
from the internal surfaces of the stone and back out the
top. At this point, the beam is again refracted, breaking
into the rainbow colors of the spectrum, a phenomenon
known as dispersion. It is in this last stage that the
diamond's fire and sparkle are visible.
All these activities indicate why the greater a stone's
clarity, the greater its brilliance. Therefore, the most
valuable white diamonds are those that are very clear
and virtually colorless.
A diamond's clarity is determined by any external irregularities
and the number of "inclusions" in the stone--that is,
imperfections created by nature when the diamond was formed.
Remember, these gems were formed deep within the earth's
core more than 100 million years ago and brought to the
surface by volcanic eruption.
As a result, most diamonds do contain some inclusions,
formed during their crystallization process, but many
are microscopic in nature and can be glimpsed only under
powerful magnification. When inclusions do not interfere
with the passage of light through the stone, they do not
affect its beauty.
Making the Grade
Inclusions such as spots, bubbles or lines are marks that
make each stone unique, but generally speaking, the fewer
the inclusions, the more valuable the stone. According
to the quality analysis system of the Gemological Institute
of America, clarity is graded on a scale ranging from
"flawless" to "imperfect." To be graded "flawless," a
diamond can have no internal or external inclusions. The
next grade, IF, meaning internally flawless, indicates
that a diamond might have minor surface blemishes but
is internally clear.
The next lower grade for diamonds is VVS (1 and 2), or
very very slight inclusions, which are difficult to see
without magnification. These are followed by VS (1 and
2), signifying very slight inclusions to SI, (1, 2 and
3) for slight inclusions. The succeeding grades of I 1,
I 2 and I 3 indicate inclusions that are visible under
10x magnification as well as to the naked eye. (Don't
bother looking at any gem under more than 10x magnification
for other than curiosity's sake. What you will see under
higher magnification will not affect the beauty of the
You may not always be able to see the difference between
stones that are similarly graded or even a grade apart,
but understand that a diamond's value decreases with each
downgrading of clarity. For example, the difference in
price between a VS 1 quality stone and an SI 1 can be
as much as 20%, all other things being equal.
Of course, the degree of clarity will be determined by
your budget and preference, but the most common grades
in jewelry range from flawless to SI. Lower grade stones
are more common in fashion jewelry rather than in engagement
While the shape of a diamond does not influence its quality,
certain shapes might reveal additional inclusions. For
example, an emerald cut, with its elongated facets and
flat table, is more likely than other shapes to reveal
a poor color grade or many inclusions.
What it Means
Your certificate is an important tool for evaluating the
clarity of your diamond because many flaws are invisible
to the naked eye, making it easy to make mistakes. The
laboratory grading the stone uses expert graders and highly
sophisticated gemological instruments. Clarity is judged
by the number, placement and nature of inclusions visible
under 10X magnification.
A plot of your stone showing the top and bottom views
may be included to illustrate the exact placement of the
stone's internal and external markings. Like human fingerprints,
these designs imprinted by nature into your diamond are
what set your stone apart from all others.