|
Beyond the
Diamond 4Cs - Diamond 5C's
When
considering the purchase of a diamond, it is imperative to study
diamond education. At Beyond the 4Cs we believe diamond education
leads to satisfied customers. We strongly urge you to learn, more
than just the basics, we recommend "beyond the 4cs" and
you've come to the right place.
The 4 C’s
of diamond grading are not four C’s at all but rather B followed
by three C’s. The B stands for brilliance, the most important
attribute of a gem grade diamond in that the beauty of a diamond is
actually the beauty of the brilliance of light. Cut, the proportions
and finish of a diamond, are what determine diamonds optical
qualities and cut (brilliance) grading assesses the nature of those
optical qualities that make up diamonds brilliance – the amount
of light and the nature of and balance of light returned to the
viewers eye. Brilliance (cut) is the most important consideration in
the evaluation of gem grade diamonds, diamonds with color at J or
above and clarity above SI-2. The brilliance (cut) of a diamond
influences the diamonds value and price by as much as 25%. Yet is it
the least documented or understood when purchasing a diamond.
For diamond
education purposes, in describing the make of a diamond two words are
used, shape and cut. Shapes, such as round brilliants, emerald
shapes, radiants, princess, pears, ovals, marquis and hearts indicate
the overall appearance and faceting style of any one individual
diamond. Cut grading of a diamond classifies the quality of any
individual diamond shape by its proportions and finish, with each
diamond shape having unique proportional and finish characteristics.
Proportions,
the empirical data of degrees of angle, measurements and percentage
of measurements, record the specific characteristics of each shape of
diamond. For round diamonds all measurements are expressed in
relation to that diamonds average diameter whereby a table
measurement of 55% or a total depth measurement of 60% are
expressions of their percentage of the averaged diameter of the
diamond. Measurements for elongated diamond shapes such as emerald
cuts, radiant cuts, and ovals are expressed as a percentage of the
width alone. Degrees are used to measure the angle of the crown (top,
above the girdle) and pavilion (bottom, below the girdle) of the
diamond in relationship to the plane of the girdle (diameter). Finish
is an interpretive observation of the quality of both the polish of a
diamonds exterior surfaces and its symmetry, the relationship of one
cutting feature to another, the alignment of the diamond. Each
diamond shape is graded by the cut characteristics of its proportions
and finish. Both the empirical data of the proportions and the
interpretive observation of the finish are considered in a judgment
of the overall cut grade assigned to a diamond.
It was
Gemological Institute of America that first developed a standardized
grading system for round diamonds, classifying the empirical data and
interpretive observations into four cut grades, those being Make
Class One, Make Class Two, Make Class Three and Make Class Four.
The American
Gem Society has further refined the GIA grading system with strict
definitions of variance for both the proportions and finish of a
diamond in a system that rates diamond brilliance (cut) by variances
from zero (ideal) to ten (poor). Today, the best system of brilliance
(cut) grading for fancy shape diamonds (standard shapes other than
round) is that of the Accredited Gem Appraisers and Mr. David Atlas,
a system that rates diamonds into three general brilliance (cut)
quality categories that are described as fine, average and below average.
Brilliance
(cut) grading defines the quality of the optical properties of
diamond as those optical properties relate to the light we perceive
in viewing a diamond and as it is said, the beauty of diamond is,
simply, the beauty of light. Just as color grading defines the degree
of colorlessness and clarity grading defines the degree of
flawlessness, cut grading addresses the degree of a diamonds
brilliance. Once a diamonds clarity and color values are in the gem
grades whereby there are no eye visible inclusions (flawlessness) and
no apparent yellowing (colorlessness), the optical properties
(brilliance) become the most important determinant of diamonds
beauty. Stating that point at which a diamond becomes of gem grade is
a value judgment unique to the experience and values of each
individual gemologist with many feeling that for a one carat round
brilliant cut diamond, the point on the GIA grading continuum at
which such a diamond becomes of gem grade is J color and SI-2 clarity
with Make Class Two cut.
Deeper diamond
education is needed by consumers, because a diamonds degree of
brilliance is not as easily conceptualized as its color and clarity
and because most sellers use spotlights to cheat (artificially
enhance) cut quality you are in a buyer beware situation if you are
not purchasing your diamond from a Graduate Gemologist who knows how
to represent Cut (brilliance) properly. A precise represenation of
cut can only be achieved using technically advanced proportion
grading instrumentation as described below.
These
proportions can only be measured using a precisely-tuned instrument
called a Sarin Dia Mension proportion grading machine. The same
machine used by AGS. View a Sample Sarin Diamond Grade Report (DGR)
which you should request on all diamonds greater than .25ct.
No machine can
measure a diamond's quality of finish (this work is done by our
highly trained gemologists). The AGS 0 cut grade also means that a
diamond possesses ideal symmetry and polish. Learn more about Ideal
Cut Diamonds.
Flash,
dispersion, blend and scintillation are properties of diamonds cut,
the prime determinants of the light display produced by each diamond.
Some diamonds are bright and dance with life whereas other diamonds
are obscure, dull and lifeless. In that the beauty of diamond is the
beauty of light, cut is the prime determinant of diamonds beauty in
any given color or clarity grade.
As you can see
diamond grading has several components for consideration. Whereas
color grading relates to the continuum from colorlessness to yellow,
clarity grading deals with the position, nature and size of
inclusions and cut determines the flash, dispersion, blend and
scintillation of light. Color is relatively easy to understand,
followed by clarity and the visibility of inclusions (flaws). Cut on
the other hand is more difficult for the mind to “picture”
and therefore, although it is the single most important determinant
of diamonds beauty it is the least understood quality component. The
blame for this long accepted ignorance is in the retail jewelry
industry because the retail jewelry industry has relied on
professional salesmen rather than professional gemologists to
demonstrate diamonds to the public. Further, retail jewelers have,
for too long, used spotlights to demonstrate diamonds and those multi-directional
spotlights can make a jelly glass sparkle. As the educational
efforts of Gemological Institute of America are resulting in an
industry wide class of professional gemologists, cut is beginning to
be properly represented and is, slowly, gaining its preeminent
position as the single most important attribute of a diamonds beauty. |
