Private consultants on the 4 C's of diamonds - color, cut, clarity, and carat weight.
Cut
By the beginning of this century, the art of cutting diamonds had
been so refined that a precise mathematical formula was developed.
It called for most diamonds to be cut with 58 facets, each placed
at a precise angle to the other. It is the work of a master cutter
that allows the diamond to be cut in such a way as to permit the
maximum amount of light to be reflected through the diamond. And
a good cut, or make, has more scintillation, more sparkle.
Color
Totally colorless diamonds are very rare and represent the highest
color grade. Because it is totally colorless diamond that acts as
a prism, allowing light to pass effortlessly through the diamond
and be transformed into rainbows of color. Diamonds are occasionally
recovered with a strong, bright color - green, red, blue, amber.
These Fancy Color diamonds, when large, are collector's items -
fetching commensurate prices.
Clarity
Refers to the degree to which a diamond is free of interior or exterior blemishes, or inclusions. Diamonds, more than any other gemstone, have the capability to produce the maximum amount of brilliance. And a diamond that is virtually free of the passage of light through the diamond. To determine a diamond's clarity, it is viewed under a 10-power magnification by a trained eye. Minute inclusions neither mar its beauty nor endanger its durability.
Carat-Weight
As with all precious stones, the weight - and therefore the size -
of a diamond is expressed in carats. The carat originated in a natural
unit of weight: the seeds of the carob tree (keration). Diamonds were
traditionally weighted against these seeds until the system was standardized
and one carat was fixed at 200 milligrams (1/5 of a gram). One carat
is divided into 100 "points" so that a diamond of 150 points
weights 1.5 carats. Size is the most obvious factor in determining
the value of a diamond. But two diamonds of equal size can have very
unequal values, depending on their quality. And diamonds of high quality
can be found in all size ranges.