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The cut of a diamond refers to its proportions. Cut
is almost (with the exception of very poor clarity
stones) totally responsible for fire and brilliance.
Of the 4Cs, the cut is the only aspect over which
man is the sole influence; the other three Cs are
dictated mostly by nature. At Grissom’s we feel
cut is the first and most important factor of quality.
Cut means much more than just a stone's
shape although the two words are often confused. Shape
varies by personal preference or nature’s demands
while cut refers to the quality of the stone's reflective
ability as well as its balance or symmetry. Whatever
the shape, a well-cut diamond is better able to reflect
light.
A diamond's ability to reflect light
determines its display of fire and brilliance. Modern
diamonds are generally 58 facet designs--a facet is
a separate flat surface or plan. These facets follow
a mathematical formula and are placed at precise angles
in relation to each other. This balance will maximize
the amount of light reflected back out of the diamond
creating fire and brilliance, and off the stone's
surface for luster.
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Color grades rate or measure the
amount or presence of body color in a diamond.
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Fancy yellow diamonds like these are very rare--and
very valuable - click
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The absence of color in diamonds is very rare and
highly prized. Since the late 90s, the demand for platinum has increased
consumer demand for high color or colorless diamonds. Most diamonds
mined in nature have traces of yellow, some brown or gray. Color
is caused in diamonds by minute traces of other elements--for example,
the presence of nitrogen will cause a yellowing while boron will
cause a noticeable blue tint. Most diamonds in our inventory at
Grissom’s will range from D (colorless) to K (very light yellow)
D-E & F graded diamonds are called colorless and appear blue
white. Many customers prefer (by their opinion of beauty) very slightly
tinted colors (like I-J-or K); these stones cost less and still
look white when mounted.
Diamonds come in all colors of the rainbow, even
more shades than any colored gemstone. The most rare diamond colors
are red, pink, and blue. Diamonds that display enough of a hue,
or nuance of color to be desirable, are called fancy-colored diamonds.
Yellow diamonds are most known to consumers as canary (a popular
salesman’s slang) for light fancy to vivid fancy yellow. Brown--although
it had it time of popularity in the eighties--is the least rare
and is only requested occasionally. Strong brown stones have been
over-produced from Australian mines and even have been poked fun
of in movies and commercials in recent years.
Color is an important factor to beauty, rarity,
and value because it is something a consumer can see without the
aid of equipment. It is vital to buy a color you are happy with
as you will notice the color only secondly to the fire in a diamond.
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Clarity grade refer to the
degree to which the diamond is free of inclusions and blemishes.
Nature produces very few things that man calls perfect. Perfect
or Flawless in diamond grading means a pure clean stone under 10x
magnification. 10x is the worldwide industry standard for diamond
grading. Most diamonds have internal flaws known as inclusions,
and external characteristics called blemishes. These clarity characteristics
are evaluated under 10X magnification, by trained diamond graders,
based on the number, nature, size, location and color of each characteristic.
Clarity characteristics are also used to distinguish one diamond
from another. A diamond's inclusions are often used as identification
as they make each diamond one-of-a-kind. Flawless diamonds are extremely
rare and command the highest prices, but finding a diamond with
minute inclusions can reduce the cost of the stone without detracting
from its beauty or durability.
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Carat is a weight measurement exclusive to the diamond and gem
industry it was adopted in the United States in 1913. A metric
Carat is equal to .200 grams or 200 milligrams. A carat is subdivided
by 100 points (think of a point as one percent of a carat). Carat,
abbreviated as (ct), is often confused with Karat (kt); both are
pronounced the same, but Karat is a US gold purity rating. All
gems do not look the same size at a given Carat depending on depth
of cut and specific gravity of a given gem type. Sapphire and
Ruby (corundum) have higher specific gravities making them weigh
about 30% more per volume or look 30% smaller.
Many times a diamond that sounds like a bargain will be cut much
too deeply giving weight without adding to the visual size and
costing the stone fire, brilliance, and luster. Very deeply cut
stones may also be more difficult to set in an appealing manner
-- so remember, a carat is not just a carat. Use the diagram below
to help understand proper measurements based on carat for the
various shapes.
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Carat |
0.05 |
0.10 |
0.20 |
0.25 |
0.30 |
0.40 |
0.50 |
0.70 |
Øm/ m |
2.5 |
3.0 |
3.8 |
4.1 |
4.5 |
4.8 |
5.2 |
5.8 |
h m/ m |
1.5 |
1.8 |
2.3 |
2.5 |
2.7 |
3.0 |
3.1 |
3.5 |
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Carat |
.90 |
1.00 |
1.25 |
1.50 |
1.75 |
2.00 |
2.50 |
3.00 |
Øm/ m |
6.3 |
6.5 |
6.9 |
7.4 |
7.8 |
8.2 |
8.8 |
9.4 |
h m/ m |
3.8 |
3.9 |
4.3 |
4.5 |
4.7 |
4.9 |
5.3 |
5.6 |
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