There are basically three types of cutting
patterns, the brilliant cut, the step cut and
the mixed cut (a combination of brilliant and
step cuts). Sometimes diamonds with modified
cuts are described both as to shape and faceting
pattern in order to minimize confusion. For
example, an oval shaped stone, which has a
brilliant cut crown and a step cut pavilion,
might be referred to as a "modified oval" or an
"oval mixed cut".
Some of the fancy shapes are better suited
for retaining the maximum weight of the more
flat forms of diamond rough called macles and
flats, and many are also cut from the less
perfectly shaped octahedral and dodecahedral
crystals. There are many other shapes
(trilliant, bagette, etc.) and many branded
cutting patterns which occupy specialized niches
and more limited market positions, but we will
not cover them here.
Factors important in selecting a fancy
shaped diamond include all of the 4C's as
they apply to the round shape. However,
additional considerations come into play when
considering fancy shapes such as the overall
appearance of the outline of the girdle of the
stone, the "bow tie" effect and the
length-to-width ratio. Finally, one may ask, how
does shape affect price? So here we will
consider each shape separately and the factors
which are important in how they impact beauty
and price.
Currently there is no widely accepted "ideal"
range of proportions for the fancy shaped
diamonds. However, these may be developed in the
future because it is known that the American Gem
Society is working on this issue (see
www.gemappraisers.com for details. This is
probably the best classification of cut
proportions in fancy shapes currently
available.)
When looking at the general appearance
of fancy cut diamonds, make sure that the stone
is appealing to your eye and that it is
bilaterally symmetrical. In other words, if you
draw an imaginary line down its center length or
across its width (excluding heart and pear in
the latter case), one half of the stones should
be shaped exactly as the other half. Also look
at the shape of the pavilion, especially on
emerald cuts, from all angles to make sure it
isn't too deep and doesn't bulge excessively, an
indication of extra weight retention and perhaps
a reduction in light return (brilliance).
In many fancy shaped diamonds (marquise,
pear, oval, emerald and heart shapes) the
pavilion facets do not culminate at a point at
the tip of the pavilion, but rather form an
edge, called the "keel line". However, for
grading purposes this is still referred to as
the culet and should be judged accordingly.
Girdle width will vary between greater
extremes on some fancy shapes compared to the
round brilliant. These include the marquise,
pear and heart, where the girdle tends to be
thick or extremely thick at the tips of the
stone and in the cleft of the heart-shaped cut.
Also, the princess cut, which has square
corners, may have an extremely thin girdle in
these areas. These situations are frequently
encountered with fancy shapes, and attention
needs to be paid to the potential problems of
excessive weight vs. danger of cracking or
chipping in diamonds with extremely thick or
extremely thin girdles, respectively.
The length-to-width ratio is important to a
stone's appearance, and for the marquise shape
the preferred range is 1.75-2.25: 1.00. Marquise
diamonds frequently show a bow tie, so try to
find a stone in which this is minimal or absent.
This shape of diamond in a ring accentuates the
length of the fingers.
As a % of the diamond's width, the better cut
marquise will have table % in the range of
53-63% and total depth % (crown+girdle+pavilion)
of about 58-65%.
The cost of a 1ct., D, IF marquise is about
20% less than that of an identical round
diamond. For a 1ct., G, VS2 stone, the marquise
cut is only about 7% cheaper than the same round
diamond.
PEAR - The pear shape, like the
marquise, usually has the 58 facet brilliant
pattern, but can also be cut with different
numbers of pavilion mains of 8,7,6 or 4 facets.
In a pear, look for a well-shaped head and
even shoulders with an optimal length-to-width
range of 1.50-1.75:1.00. This shape in a ring
will make the fingers appear longer. Pear-shaped
diamonds work equally well as pendants and are
exceptional as drop earrings.
Ranges for the well cut pears for table % and
total depth % are about 53-63% and 58-65%,
respectively.
The relative cost of a 1ct., D, IF pear
shaped diamond is roughly 25% less than an
identical round stone, but a 1ct., G, VS2 pear
is only 20% less than the cost of an identical
round.
OVAL - The oval, as with the above
examples, is seen most frequently cut in the
standard 58 facet brilliant pattern, but again
can have a varying number of pavilion mains
facets ranging from 4, 6 or 8.
For ovals, look for even, well-rounded ends
with a full body having an optimal
length-to-width range of 1.33-1.66: 1.00. This
shape of stone in a ring accents finger length,
and also works nicely as stud earrings.
Higher cut quality ovals, as with the
marquise and pear, have table %'s of about 53-
63% and total depth %'s of 58-65%.
The relative cost of an oval diamond of 1ct.,
D color and IF clarity is roughly 25% less than
an identical round stone, but a 1ct., G, VS2
oval is only 20% less than the cost of an
identical round.
RADIANT - The radiant cut is a
patented name and cut called a cut-cornered,
square/rectangular (depending on the overall
shape) modified brilliant on GIA grading
reports. It has a total of 70 facets, there
being 25 crown, 8 girdle and 37 pavilion facets.
The truncated corners may aid in avoiding or
minimizing possible chipping problems posed by
extremely thin girdle widths in these areas of
the stone.
Generally, a ring with a square cut radiant
tends to shorten the appearance of the longer
fingered hand.
Radiants of higher cut quality will have
table %'s of about 59-69% and total depth %'s
ranging from about 59-69%. Deep pavilions are
often seen on many radiants and princess cuts
and contribute to the increased total depth %
seen in these stones. However, this extra depth
is often necessary to bring out the maximum
brilliance in the stone.
The comparative cost of a 1ct., D, IF radiant
diamond is roughly 33% less than an identical
round stone, but a 1ct., G, VS2 radiant is only
about 20% less than the cost of an identical
round.
PRINCESS - The princess cut is called
a square/rectangular modified brilliant in GIA
grading reports. It may have either 50 facets
(21 crown, 4 girdle, 25 pavilion) or 58 facets
(21 crown, 4 girdle, 33 pavilion), depending on
how the pavilion is cut.
This cut of diamond is frequently a square
shape and therefore shortens the appearance of
the longer fingered hand. The princess cut has
sharp, squared-off corners, and if the girdle is
extremely thin in these areas, chipping or
cracking may occur more easily.
Princess shapes of high cut quality usually
have a table % in the range of roughly 60-75%
and a total depth % of about 65-80%.
As with the radiant, the cost of a 1ct., D,
IF princess diamond is roughly 33% less than
that of an identical round stone, but a 1ct., G,
VS2 princess is only about 20% less than the
cost of an identical round.
EMERALD - The emerald cut is not a
brilliant cut, but is called a step cut. Step
cuts are comprised of larger, planar facets
which act like mirrors. The emerald cut has 58
facets, with 25 crown, 8 girdle and 25 pavilion.
Because of the angle, size and shape of the
facets, the emerald cut shows less brilliance
and fire (dispersion) than the other brilliant
and modified brilliant cut diamonds. However,
the emerald cut stone reveals a classic and
aristocratic elegance and beauty not seen in
other cuts.
Because of the open and large, plate-like
nature of the facets, it is highly recommended
that you consider staying at higher color (D-G)
and clarity (IF-VS2) grades than you might with
a brilliant cut stone because they are more
likely to become visible at lower grades. Also,
check to make sure that all the facet edges
appear parallel in the face-up position. If they
aren't, it can be pretty obvious at times.
The emerald cut offers a touch of regal
elegance as the center stone in a ring, and the
most attractive proportions are a
length-to-width ratio range of 1.50-1.75:1.00.
However, some prefer a more square look with a
ratio in the range of 1.30:1.00. Obviously, the
more square the shape, the more it compliments
the longer-fingered hand, and the more
rectangular, the better suited it is to the
shorter-fingered hand.
The better emerald cut diamonds, like
radiants, will have table %'s of about 59-69%
and total depth %'s ranging from about 59-69%.
Like both the radiant and princess, the cost
of a 1ct., D, IF emerald cut diamond is roughly
33% less than that of an identical round stone,
but a 1ct., G, VS2 emerald is only about 20%
less than the cost of an identical round.
HEART - The heart shape is a brilliant
cut, which can also be modified so that the
number of pavilion mains may be 6, 7 or 8.
In a heart cut it is important to look for a
perfectly symmetrical appearance where the lobes
(top arches) are of even height and breadth, and
the overall shape pleasing.
The better cut heart shapes will have a
length-to-width ratio of just about 1.00:1.00,
with a little variation from about 0.98:1.00 to
1.02:1.00.
This shape is seen frequently in pendants,
but is suitable for most any purpose.
The well-cut heart shaped diamonds will have
a table % in the 53-63% range, and a total depth
of about 58-65%.
Roughly comparable with the pear and oval
shapes, the relative cost of a 1ct., D, IF,
heart shaped diamond is approximately 25% less
than an identical round stone, but a 1ct., G, VS
heart is only about 20% less than the cost of an
identical round diamond
