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♦The
4C's (carat/cut/color/clarity)♦
♦
Carat Weight
Carat is the unit of weight for all gemstones. One carat is
subdivided into 100 "points". Therefore a diamond measuring
75 points is 3/4 carat in weight, or 0.75ct. There are five
carats in a gram. The word "carat" comes from the seed of
the carob tree pod which is found in tropical climates.
These seeds were used until this century to weigh precious
gems.
♦
Cut
Cut, sometimes the forgotten "C", ensures that a given stone
has maximum brilliance and sparkle which would not be the
case were the stone cut for weight alone. Simply put,
when looking at a diamond, if it doesn't catch your eye or
if it doesn't flash in the light, it's probably not well
cut. Good cutting is what brings fire to the ice.
   
♦
Color
Ideally, a diamond should have no color at all, like a drop
of spring water. Increasing degrees of body color are
measured on a scale ranging from no color at all (D) to
deeply colored (Z). Beyond "Z" is the range where the
diamond's color is vivid and rich, called "fancy colors".
Diamonds of known color are used as comparison stones for
color grading. Grading is done by comparing the diamond to
be graded against these "master stones" under either
artificial or natural north daylight ( in the Northern
Hemisphere). A machine called the "Colorimeter" can be used
for color grading but there is no substitute for the trained
human eye.
♦
Clarity
A diamond's clarity is determined by the number, nature,
position, size and color of internal characteristics called
"inclusions" and surface features called "blemishes". These
irregularities occurred in the liquid magna (volcanic rock)
within which the diamond was created. Diamonds are mostly
pure carbon, however, during crystallization other minerals
nearby, or even other bits of carbon forming more quickly
may have become trapped within the cooling mass. These show
themselves as the various characteristics which make up the
clarity of a diamond (included crystals, feathers, clouds
etc). Clarity is measured on a scale ranging from:
-
Flawless (FL)
No inclusions or
blemishes are visible to
a skilled grader using
10× magnification
-
Internally Flawless
(IF)
No inclusions and only
minor blemishes are
visible to a skilled
grader using 10×
magnification
-
Very, Very Slightly
Included (VVS1 and VVS2)
Inclusions are difficult
for a skilled grader to
see under 10×
magnification
-
Very Slightly
Included (VS1 and VS2)
Inclusions are clearly
visible under 10×
magnification but can be
characterized as minor
-
Slightly Included
(SI1 and SI2)
Inclusions are
noticeable to a skilled
grader using 10×
magnification
-
Imperfect (I1, I2,
and I3)
Inclusions are obvious
under 10× magnification
and may affect
transparency and
brilliance
The final
clarity grade is usually determined by how easy the
inclusions and blemishes are for the grader to see.
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