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Learn
To Identify the Common Heavy or Deep Cut Diamonds:
Diamonds are frequently cut for weight retention rather
than to produce maximum brilliance. These �undersize
diamonds� often weigh more than if they were cut correctly
and can therefore can be sold for for a larger profit.
 For
example: an ideal or very fine cut one carat diamond
measures 6.4 to 6.5 millimeters in diameter. If
you were to measure the diameters of most one carat
diamonds on the market today, you would find many to
measure between 5.9 and 6.3 millimeters.
These 1.00 carat, inferior
cut �undersize diamonds� are no larger in diameter than
ideal or fine cut diamonds which weigh 0.75 to 0.99
carats, and they exhibit significantly less brilliance.
We encourage you to choose a diamond that has ideal
to very fine cut. |
Many
diamonds today are cut improperly. A flawless, colorless
rough diamond crystal can be cut to very fine or ideal
proportions to deliver the greatest balance of dispersion
and brilliance, or it can be cut to inferior proportions
which yield a diamond that displays very little brilliance
but weighs slightly heavier.
To
understand diamond cut, it helps to understand how light
reacts within a diamond. When light enters a diamond or
any given material it bends or refracts. The degree
to which it bends is called the refractive index. The
refractive index of diamond is 2.41, the highest of any
natural transparent gem. In diamond the maximum angle
of refraction is 24.5 degrees. This is called the
critical angle. Light traveling through a diamond is reflected
if it strikes a surface outside the critical angle. Light
striking a surface inside the critical angle will be refracted
out of a diamond. The critical angle is represented as
24.5 degree cone in the diagram.
The
Information included below is based on information made
available by Gemological Institute of America and the
American Gem Society. These two institutions are the
most honored in the world of gemological science.