It was the Japanese that first discovered the Hearts & Arrows (H&A)
effect. Ideal cut diamonds were the rage in Japan, in the 80s through
to the early 90's. The Japanese are well known for their extremely high
standards of quality. It is in this spirit, that they demand only the
highest quality when it comes to diamond cutting. Cut grades of "Excellent",
"Super Excellent", and "Triple Excellent", assigned
by the Japanese labs, were very popular. It was not long before they discovered
that diamonds cut to these exacting standards were known to show the 'cupid
effect', or a visual pattern of 8 hearts while looking down through the
pavilion and 8 arrows when viewing the stone in the table up position.
Through time, diamonds that display this effect' became known as 'hearts
and arrows' diamonds in the trade.
Soon after, the Japanese designed a special magnifying viewer to show
this phenomenon, called the Hearts & Arrows Scope.
These diamonds were known for their exceptional beauty, and it did not
take long before demand for them spread to the rest of the world. Spurred
by the premium that people were willing to shell out for H&A diamonds,
more cutters strive to produce the H&A pattern during their cutting
process, and hence H&A diamonds are widely available nowadays.
The IGI, the CGL (Central Gem Laboratory) in Tokyo or Antwerp grades
H&A and also the Zenhokyo gemological laboratory of Japan gives ratings
for hearts and arrows, the A-grade being best. However, I opine that it
is not necessary to get a grading for H&A because it is a very observable
To view the H&A pattern, place the diamond on a black diamond rest
and view it with the H&A Scope/Viewer. Any good jeweller that sells
H&A diamonds will have such a scope. They have to prove to you that
the diamond is indeed H&A with this viewer.
What do H&A patterns mean?
Only if the stone is cut to super-symmetry, can we see the H&A pattern.
The Hearts are evidence of the extreme level of precision to which the
diamond has been cut, particularly on the pavilion. If lower
girdles deviate too much from each other, the size of the hearts and/or
clefts in the hearts will vary and not show consistency. Viewing the pavilion
and the consistency of its pattern demonstrates the precision to which
the diamond has been cut (along with viewing the arrows). That is why
it is important for us to view and photograph this phenomenon, called
the H&A pattern.
However, seeing the H&A pattern does not guarantee
that the diamond will perform! The presence of the H&A pattern does
not mean that the diamond will definitely look good!
Do all ideal cut diamonds display the H&A pattern?
Most definitely not. A diamond can be cut to Tolkowsky's ideal proportions and not display the H&A pattern. Having the diamond graded as AGS Ideal or GIA Excellent for cut does not mean that the diamond will display the H&A pattern. AGS and GIA do not grade a diamond's cut pattern.
Are all H&A diamonds ideal cut?
Again, definitely not. Diamonds can be cut outside the ideal
range of any reputable diamond laboratory and still display the H&A pattern. Observation of the H&A phenomenon attests to the diamond's super-symmetry, and nothing more.
Value of an H&A diamond
The presence or phenomenon of the arrows indicates that the pavilion
mains are reflecting light back up into the face of the observer in
direct light conditions (necessary for strong fire), and provide points
of contrast in diffuse light conditions.
In direct light this provides for the most fiery of diamonds (when coupled
with other facets directing light at those high angles also provides for
superior scintillation) and in diffuse light provides for some of the
most brilliant diamonds due to the high contrast.
Although an H&A diamond is not a guaranteed performer, it does ensure superior scintillation if the diamond is well cut (that is, all other aspects of the diamond's proportions are in order). In addition, the arrows pattern is observable and it is aesthetically pleasing. Therefore, H&A diamonds command
a premium. To some,
super-symmetry may not be important, but personally, I think an H&A diamond
looks far better than one which has poor symmetry.