Hearts on fire have a traditional ideal cut facet arrangement
and near traditional angles for the ideal (The angles vary much
less than most modern cut stones from the tradtional ideal).
The diamond is laser inscribed on the girdle “HEARTSONFIRE” and
when viewed through a certain device (several on the
market–“firescope” is the name of one) a pattern of hearts is
seen in the pavilion up position and arrows in the crown up
position. The perfect alignment demonstrated by this optical
device demonstrates extreme care in aligning facets. This
devise also demonstrates that deviations from these angles
results in the leakage of light through the bottom of the stone.
The September issue of Modern Jeweler has the best definitive
diuscussion about cutting and what differentiates some of the
trademarked cuts.
Aren’t the hearts, in fact caused by leakage from the stone?
Another question. I have a brochure that suggests that an .85ct
“Hearts on Fire” diamond has the spread of a 1ct “regular stone”.
My experience suggests that most stones are spread a little
already. Wouldn’t these just be swindled a little more than
average?
Bruce D. Holmgrain
Marylands first JA certified Master Bench Jeweler
Http://www.goldwerx.com
jakeworth@goldwerx.com
I don’t sell Hearts of Fire stones but I have worked with the
company that markets them. They are exceedingly close to ideal
cuts if not actually having all the necessary angles to qualify
as an American Ideal Cut stone so if you have heard that an .85
ct diamond looks like a 1 carater you misheard. What you may
have heard and what most of the ideal cut sellers I know (like
myself) often do say is that you can buy a smaller stone, but
because they are so brilliant, they will come across with a
bigger feel.
Bruce:
Hearts on Fire diamonds are cut to absolute ideal and therefore
would leak the least amount of light possible. Nothing is known
to be better than ideal. A spread stone is one cut for maximum
diameter only. Hearts on fire diamonds will often actually be
slightly smaller in diameter. The hearts are caused by the
faceting only and illustrate the precise cutting work. The
brochure you speak of may be from a competing “brand”.
Best;
Steve
Another uncertified Michigan bench jeweler
Hearts on Fire diamonds are cut to absolute ideal and therefore
would leak the least amount of light possible. Nothing is known
to be better than ideal.
do keep in mind, Steve, that Tolkowsky proportions are only one
definition of “ideal”. At the time those were computed, there
were several other experts who arrived and somewhat other
figures, and our current use of tolkowsky proportions is slightly
arbitrary in nature. The reason is that ideal proportions are
intended to maximize both brilliance and dispersion, but the two
qualities are somewhat in conflict. A stone that truely
maximizes dispersion will have too small a table for maximum
brilliance, and a stone maximized for brilliance will have little
dispersion. The Tolkowsky proportions attempt to find the best
balance, and do so quite well. but it does become slightly a
matter of opinion, as well, as to what actually constitutes the
best balance as well as the best overall appearance. it is for
this reason that stones defined as ideal do actually have some
variance in table size. Some markets prefer a 53% table, and
other prefer closer to 56%. And while light leakage is kept to
a minimum throught the pavilion, the issue of exactly where the
light DOES come out of the crown is a bit more complex. One
could spread it over a wide viewing angle, or into a narrower and
brighter cone, for example. Remember, too, that these
proportions only specify table size, crown and pavilion angles,
girdle thickness, etc. They don’t actually require the standard
round brilliant pattern of facets. One could have considerable
fun with facet designs while still maintaining tolkowsky
proportions.
As to hearts on fire, (and as, I think, the guy who started
this thread), all I know is the one stone I saw, labeled as a
hearts on fire cut), was gorgous, cut to great precision in facet
placement and arrangement, but was NOT the standard 58 facet
round brilliant. As I said, the pavilion was done slightly
differently, with 16 mains, and 16 “girdle” or “break” facets,
and the latter were carried farther towards the culet than is
done with most standard round brilliants. The result was very
beautiful, brilliant and full of fire, but slightly different in
face up appearance too. I didn’t have the stone around long
enough to dwell on it in greater detail, or to take time to look
for laser etching on the girdle or other such identifications. I
was just making the platinum mounting, and it got then passed to
our setter for setting. It’s possible the store used a “hearts
on fire” display box for another stone, but I doubt it, as the
store’s job envelope specifically called the diamond a “hearts on
fire” stone. And these folks aren’t the sort to fool around
with errors, or with cheap stones.
Anyway…
Peter Rowe
Hearts a Fire are just another cutting style , a good one for
sure, but there is no ideal cutting style and there are many ,
many different cutting styles that can arguably be said to be
the most brilliant. This discussion is like the school yard
argument about who is the prettiest girl in the school.
Peter:
I read with great interest your discussion of brilliance vs
dispersion concerning the Hearts on 'Fire Diamond. I would be
interested in whether you have any references about this. As far
as I can tell from my reading brilliance might be higher for
colored stones with low crown angles, but dispersion requires a
high crown. I haven’t seen any discussions of crown angle vs
dispersion and brilliance. Thanks for all your great posts.
Roy (Jess)
I’m continuing to follow this thread with interest. Last week, I
had a chance to inspect my first “hearts on fire” diamond. It was
a firey little thing, absolutely perfect in cut… yet, it left me
a bit cold. Just a pure gut response, it seemed too perfect and
had somehow lost that human element that makes each larger
diamond somehow an individual. Somewhere between the calculations
of my exacting eyes and my less than logical emotions, the sum
fell short of the whole. Am I alone in this or are there other
folks out there that find something about these stones vaguely
disturbing?
Jane
Jane Armstrong/@Jane_Armstrong
To clarify–Peter-I think the stone with the variation of facet
pattern you saw was possibly the new Gabrielle cut (there are a
few other new ones as well–Shachter & Namdar from Isreal has a
striking new round cut as well). I have written several
articles that have appeared in Rap related to cut (One was about
what Tolkowsky really said) and discussed new technology I was
involved with, that evaluated light leakage vs angles, table
size etc. Modern Jeweler emphasized that research along with
research we did related to symmetry in combination with certain
angles in Sept 97 issue. Peter is correct is talking about the
combination of dispersion and light return being a balance in
Tolkowsky’s mind. However, working with some rudimentary
dispersion measurement equipment, we were able to find that some
ideals did have very high dispersion while other ideals were
very quiet. The reason for the differences were not as Tolkowsky
postulated, but were there for more complex reasons. This
research led to a lab report that quantified symmetry, light
leakage and rudimentary dispersion provided by Diamond Profile
Laboratory. The lab is now relocating to Dallas, and the
original developers of the technology (including myself) are no
longer connected with Diamond Profile. For these reasons I was
asked by GIA to provide a poster session at the upcoming
Symposium on the subject and be one of the experts leading the
discussion for cut in the “Cut War Room” at symposium. Hearts
on Fire is a traditional facet pattern with angles very nearly
that of tradtional ideal angles. They have taken additional
steps to perfectly align symmetry, thereby limiting additional
light leakage. Some ideals leak as much as 7% of the light on
through the pavilion of the diamond, with most ideals around
3-6% leakage. If symmetry is perfected such as in “hearts on
fire” or “eight star” leakage is frequently less than 1%–a
significant improvement on light returned to the viewer. Al
Gilbertson
Jane,
As a cutter I have had freinds that cut diamonds for hearts of
fire and beleive me they are as perfectly cut as can be done by
hand and that should be comended…but I think that both from an
artistic and economical point of view a cutter can bring Life to
a diamond and not stand to a stringent formula and sacrifice
weight for acruacy.
I recently sold a 2 carat oval diamond that I had given a steep
crown and a small table and the results were a diamond that
sparkled from just about every direction and it was a a stone
cut out of the ridged parameters of the IDEAL cut. This is not to
say that beautifuly cut IDEAL cut it not the most admired for
accuracy and pecision. I have made trilliants that knock your
socks off and are not Idelly cut. Diamonds have an inner beauty
that can be released when cut with Heart and not just a formula.
Ron Kreml
To clarify--Peter-I think the stone with the variation of facet pattern you saw was possibly the new Gabrielle cut
Thanks very much, Al, for this info. Now it all makes sense
(the conflict between different accounts of what a hearts on fire
stone should be…) Evidentally, the stone I saw was mislabeled
as such.
Also, thanks for your interesting note on new research on cut
efficiency. I’ll look forward to seeing it published, when you
do so.
And to you Orchidians reading the post I sent a couple minutes
ago about cutting variations, pay attention to Al. He knows way
more about these issues than this ol’ 1979 trained graduate
gemologist…
Peter Rowe
Am I alone in this or are there other folks out there that find something about these stones vaguely disturbing?
No, Jane. You’re not alone. As I mentioned, I’d noticed that
the stone I saw, which I can only assume is representative
(please, someone, correct me if I’m wrong here) used a pavilion
facet arrangement that differs from the normal round brilliant
cut, with sixteen pavilion main facets (culet to girdle) and
sixteen “girdle” or “break” facets, girdle to a bit short of the
culet, with only one such between each pair of mains, intead of
the usual two break facets at each corner between mains. The
result of this is that the pavilion mains, near the culet, are
narrower. The appearance is more that of a sunburst than the
usual bunch of reflections similar to the size and appearance of
other reflections in the stone. In a normal “ideal” cut, one
gets a uniform appearance of fire and scintillation and bright
sparkles all over the stone. In the hearts on fire stone I saw,
while everything was nice and bright, I had the impression that
the area under the table, the center of the stone, appeared as a
distinctly different center zone, rather than blending into the
whole thing. While I liked the stone well enough, I can’t say I
was convinced that this pavilion pattern was an improvement.
Peter Rowe
I seem to have given this topic enough of a kick to start
something. If you find me offensive here, just let me know.
I have in my hand, a brochure titled "Hearts on Fire Diamonds",
complete with trademark. Inside, " The .85-carat Hearts on Fire
diamond has the same size diameter as the ordinary one-carat
diamond". “The fact is, a .85 carat Hearts on Fire diamond looks
as big as an ordinary one-caat diamond because they are both
exactly the same size in diameter”. It goes on to say "In
technical terms, the highest rating for cut is “Zero” with
polish and symetry finish of “Excellant/Excellant”. I believe the
polish and symetry statement. Have I forgotten this highest
rating of “Zero”? The illustrations seem to suggest stones that
leak more light through the pavillion. They also seem to indicate
??? Any more thoughts?
Bruce D. Holmgrain
Maryland’s first JA certified Master Bench Jeweler
http://www.goldwerx.com
manmountaindense@goldwerx.com
I read with great interest your discussion of brilliance vs dispersion concerning the Hearts on 'Fire Diamond. I would be interested in whether you have any references about this.
Not specifically regarding the hearts on fire cut, but the basic
principles are mostly the same regardless of the exact facet
arrangment…
As far as I can tell from my reading brilliance might be higher for colored stones with low crown angles, but dispersion requires a high crown. I haven't seen any discussions of crown angle vs dispersion and brilliance. Thanks for all your great posts.
Here’s how it works. (gemology 101… 
)
The pavilion of a diamond or other stone, to be brilliant
functions in essence as a reflector, much like a “corner cube”
reflector. The idea is that light must bound twice, first
incoming light hits the pavilion surface (which it must do within
an angle that results in it’s total reflection back into the
stone, rather than it’s refraction totally out of the stone). It
now is travelling roughly horizontally in the pavilion, until it
reaches the other side, where it again must totally reflect, in
order to now be going back out the crown of the stone. If the
pavilion angle of the stone is too shallow, light is unable to
properly make the first reflection, and leaks directly out the
pavilion. In such stones, you literally can see what’s
underneath the stone. If the pavilion angle is too steep, the
light makes the first reflection, but ends up going too close to
perpendicular to the second surface, and is lost there. The key
to pavilion angles is that they must not only maximize total
internal reflection for light entering perpendicular to the
table, but hopefully also include as wide a cone of entry angles
for the light as possible, while still letting the light totally
reflect. For colored stones with lower refractive indexes, this
can by difficult, but with diamond, you can get a fairly
substantial angular range for entrant light. The result, when
this is maximized, is the best brilliance in a stone… However,
the most efficient place for light to enter the stone for
brilliance is the table. Crown facets scatter the light more,
and loose some of it. So the larger the table, the higher total
reflectivity can be.
Crown angles are more complex, and are concerned with more than
just dispersion. Dispersion or fire, the breaking up of white
light into it’s spcetral colors, occurs when light enters or
exits the stone at an angle. The closer to the stones “critical
angle” this happens, the greater this seperation into colors, but
at least on entry to the stone, increased angle of entry is also
coupled with some surface reflectance of the light back away from
the stone instead of into it as desired. The idea is to find an
angle at which the best balance of the amount of light entering
to be refracted into colors as well as an angle that’s high
enough so the degree of that refraction is suffiencent to cause
attractive color seperation in the first place. Then, it’s also
important that there is enough of the crown facets available to
perform this refractive task. If the table is small, a large
crown facet area will result in a large degree of dispersion and
fire visible (just think of the old mine cut diamonds you’ve
seen. Tiny tables, but a heck of a lot of fire.) The size of
the table must be balanced with the area allowed the crown
facets, to both maximize brilliance with a large enough table,
and maximize dispersion with a small enough table. Finding the
best balance here is somewhat subjective, in terms of how you
define the most beautiful stone.
Also, the crown facets do more than just cause dispersion.
There is also the property of scintillation, or that sense of
sparkle and movement that you get when you move the stone or your
eye relative to the stone. If a stone has a large table, then
moving the stone around, changing the angle of view, presents
little difference in the appearance of the stone. It stays
bright, but your image of it doesn’t change all that much. With
more crown facet area, that refraction of entering and exiting
light, and the distortion of the image of the interior of the
stone that this causes, makes the diamond seem much more lively
and interesting
Couple this with the effect of facet design… A large table
means that crown facets will be individually smaller, so
individual refelctions and flashes of light will be smaller.
With a large table, you get an image of lots of confusing small
sparkles surrounding a relatively dead center, while with smaller
tables, the whole stone’s appearance is of more evenly sized
sparkles of light covering the whole area of the stone.
In general, the goal of the cutter, if cutting for beauty, is to
maximize all of these properties. But Brilliance itself, the
total amount of light reflected by the stone, is in conflict with
the functions of the crown angles. Therefor, calculating exact
maximum beauty is a bit more than doing just the math. You have
to decide what that maximum beauty actually is, first. They eye
knows it easily enough. But getting there isn’t always as clear
a set of choices.
As I mentioned, the early history of the era of “ideal cutting”
had several proponants of slightly differing cuts. One good
reference for these variants is Eric Bruton’s “Diamonds”. Some
of the variants discussed there aRe:
Tolkowsky, 1919: 53% table, 34.5 degree crown, and 40.75 degree pavilion
Johnson & Rosch, 1926: 56.1% table, 41.1 degree crown, 38.6 degree pavilion
Eppler, 1940: 56% table, 33.2 degree crown, 40.8 degree pavilion
Scan. D.N., 1970: 57.5% table,34.2 degree crown, 40.75 degree pavilion.
(note that Bruton lists angles as degrees and minutes, which I
sorta estimated above to decimal points. The decimal I’ve given
above is probably not precise, but is close enough for
discussion. I’m not gonna bother to calculate em exactly for ya
here…
The above are only the most notable of the historic variants.
Several other researchers have also published variants, and
computer simulations have added their own twists of much of this.
Factors such as the notion that the viewers head will block some
light from reaching the stone, for example, had one author
modifying figures slightly. And some of the new cuts since WW2
have also attempted to address the visual appeal of the shape and
the facet placement as well as just optical calculations.
Anyway. 'nuff for now. If you want additional discussion on
it, Bruton is a good place to start your reading…
Hope this helps.
Peter Rowe
Jane: You make an interesting point. However, you must know that
almost all diamonds under a carat are machine cut and the
machines are computer driven so there goes your human element. I
share your feeling when it comes to computer generated jewelery
designs however. I guess that’s why I don’t do production work
and prefer the “one-off” process.
Best;
Steve Klepinger
Ron,
Your post about cutting gems is right on target. Sometimes
people look to set formulas because it seems to give them some
control over the cutting process. But the truly gifted cutters
look with their heart and eyes and try to bring out the best in
the gem material, regardless of a standard cutting formula. This
is how innovation in cutting ever occurs. Also, that is why you
will see gems that have “personality”; they haven’t been cut to
ideal proportions but they were cut with a sense of style and
creativity that sets them apart. Pam Welborn
hi all
finally catching up on my e-mail, but nothing else.
there are prettier girls than others to be sure, but once one
reaches a certain point of beauty the discussion is less than
academic.
one can achieve maximum brilliance with no crown at all, as long
as the pavillion angles are correct. but such a stone would
possess zero dispersion. a diamond with narrow crown angles would
increase brilliance (according to research recently completed by
gia), but dispersion certainly suffers.
as peter says, the tolkowski cut attempts to balance these
attributes.
i heard gabey tolkowski (marcel tolkowski’s progeny) speak at a
jck seminar last year and he discussed the ’ ideal’ cut. he
stated that there are many types of cuts that release the
the emotion that we call beauty including his own cut that
has added a third row of facets on the pavillion. the
circumfrence of this third row corresponds with the table size.
it is my understanding that the first and second row of facets
(under the crown) depart from ‘ideal’ proportions. thereby
giving a greater face up size.
mr tolkowski didn’t say this but he implied that there is no
’ideal’ cut, but one could certainly say there is a tolkowski
cut.
best regards,
geo fox
Steve, You may not know that most diamonds all the way down to 1
point full cut are cut by hand and not machine. Most of the real
little ones are cut by teenagers in India or China who get paid
a copuple dollars a day. Hey its a job. Thank goodness it is
what keeps the price of diamonds so low. etienne
Etienne: Are you quite sure about that? I have always understood
that computer-driven machines were used for all smaller stones,
but then again, I could be wrong. If anyone else out there has
direct knowlege on this subject, please enlighten me.
Best;
Steve Klepinger
One of the major industries of Bombay is the diamond cutting
industry. Over the last 10 years the quality of their diamond
cutting has improved dramaticly. Today the Indian diamond
cutters cut a majority of the smaller diamonds coming from the
huge Argyle mine in Australia.
Thanks,