Diamond
Buying 101 :: Cut
The cut of
a diamond - its roundness, its depth and width,
the uniformity of the facets - all determine
a diamond's brilliance. Many gemologists consider
cut the most important diamond characteristic
because even if a diamond has perfect color and
clarity, a diamond with a poor cut will have dulled
brilliance.
The width and
depth have the greatest effect on how light travels
within the diamond, and how it exits in the form
of brilliance.
Too Shallow: Light is lost out
the sides causing the diamond to lose brilliance.
Too
Deep: Light escapes out the bottom causing
the diamond to appear dark and dull.
Cut Determines Brillance
The diamond's
proportions, specifically the depth compared to
the diameter, and the diameter of the table compared
to the diameter of the diamond, determine how
well light will reflect and refract within the
diamond.
Diameter:
The width of the diamond as measured through the
girdle.
Table:
The largest facet of a gemstone.
Crown:
The top portion of a diamond extending from the
girdle to the table.
Girdle:
The narrow band around the widest part
of a diamond.
Pavilion:
The bottom portion of a diamond, extending from
the girdle to the culet.
Culet:
The facet at the tip of a gemstone. The preferred
culet is not visible with the unaided eye (graded
"small" or "none").
Depth:
The height of a gemstone measured from
the culet to the table.
These proportions
are calculated and applied to a cut grading scale
that makes it easy to understand how well each
reflect light:
Ideal
cut: Represents roughly the top 3% of
diamond quality based on cut. Reflects nearly
all light that enters the diamond. An exquisite
and rare cut.
Very
good cut: Represents roughly the top
15% of diamond quality based on cut. Reflects
nearly as much light as the ideal cut, but for
a lower price.
Good
cut: Represents roughly the top 25% of
diamond quality based on cut. Reflects most light
that enters. Much less expensive than a very good
cut.
Fair
cut: Represents roughly the top 35% of
diamond quality based on cut. Still a quality
diamond, but a fair cut will not be as brilliant
as a good cut.
Poor
cut: This includes all diamonds that
do not meet the proportion standards of a fair
cut. These diamonds are deep and narrow or shallow
and wide and tend to lose most of the light out
the sides and bottom.
Which Cut Grade is Best?
For a diamond
with the best cut, that will look exceptional
even when viewed under a microscope, look to the
Blue Nile Signature Collection available at Blue Nile .
These diamonds reflect the most brilliance because
they are cut to the most exacting proportions,
and have the highest polish and symmetry grades
for round diamonds, and have either excellent
or very good for princess-cut and emerald-cut
diamonds.
For the best
value in a brilliant diamond, choose a diamond
with a cut grade of good or very good, and polish
and symmetry grades of very good or good.
In an ideal,
or very-good cut diamond with very good or good
polish and symmetry, consider less expensive grades
of color and clarity — look for a diamond
with G or H color and SI1 or SI2 clarity.
More About Cut
Click
here to Learn About Fancy-Shaped Diamonds
To learn about fancy shapes like oval, emerald,
radiant, marquise, pear, and princess, read about
fancy-shaped diamonds. |
