Pear-shaped Diamonds: Any tricks?

[researcher]

Hi, Everyone!
Now that I''ve found my dream stone I''m helping a friend find hers. Because so many people have rounds and princesses, she''s looking at pear-shaped diamonds. The problem is they''re not popular stones (especially in the larger sizes) so she hasn''t been able to see many 2-3 ct stones in person. As such, it''s difficult to determine what specs make for the "best" cut pears. We''re of course referencing the AGA charts, but aren''t sure if there are tricks such as trying to keep the table smaller than the depth or shooting for particular pavilion angles that would help us to choose a stone or two to call in. She really doesn''t want a large bowtie effect, and seems to prefer stones in the 1:1.55-1:1.65 ratio (she has a size 7 finger and therefore likes the stones to be a little wider). Anyway, if you can offer some advice we''d really appreciate it!!!

 

[niceice]

The only trick is to work with a reliable vendor who will be willing to pull in a few stones for you after discussing them in-depth with the cutter to be sure ahead of time that they are worthy of consideration given your particular preferences. Unfortunately pear shape diamonds and other fancy shapes can not be accurately purchsed "by the numbers" but if the dealer is willing to do a little homework then your time shouldn't be wasted.

 

[researcher]

Thanks for the quick response! You two are the best (even though that's not the answer I was looking for--I chose my princess by numbers, got the B-scope report and discovered it was VH-VH-VH)!!! Maybe I should just convince my friend to go for a round....

 

[researcher]

One other thing. On the GOG website, it states that:

"Every fancy shape except for your squares and trillion cuts have what's called the "bow-tie" effect. Because the pavilion angles around the fancies vary, this produces a "bowtie" effect in marquises, pears, ovals, and hearts. How noticeable the bowtie is depends on how deep or how shallow the pavilion is cut on that stone."

Is there a magic number (or range) in the pavilion to avoid a strong bowtie?

 

[researcher]

Anyone?

 

[elmo]

----------------
On 5/27/2004 4:13:03 PM researcher wrote:

Is there a magic number (or range) in the pavilion to avoid a strong bowtie?
----------------

When I was shopping for a pear I did not see a correlation between AGA cut class and bow tie. Maybe there is some magic involved

; I've never seen a precise description of crown and pavilion combinations to avoid. Does Diamcalc do pears? If so someone with a copy could try to figure this out.

 

[researcher]

Thanks for responding!

Did you end up purchasing a pear? If so, what are the specs? How did you weed out the bad ones?

 

[chris-uk04]

Try looking at Dave Atlas's crieria. Here's a link: Cut criteria

It's useful for looking at cuts, especially since there is so little info on fancy shapes.

 

[elmo]

----------------
On 5/27/2004 11:46:25 PM researcher wrote:

Thanks for responding!

Did you end up purchasing a pear? If so, what are the specs? How did you weed out the bad ones?
----------------

I don't have specs other than color (fancy intense yellow) and dimensions (1.50 length/width) since it has a GIA color ident report...at the lab now for the full report. It's not exactly a fair comparison because with fancy color you tend to concentrate more on color over other aspects. But a very noticeable bow tie would not have been acceptable. I saw cut class 1 stones with bad bow ties, and cut class 2 and 3 stones without it.

I liked niceice's response to this; you weed out the bad ones by working with a jeweler you trust who has the patience to bring in several things and who has a good relationship with their sources to increase the chances of getting a nice one the first time or two around.

Don't be afraid to not take the first one that is offered. The internet sellers that concentrate on round ideals and working on the low margins count on making the sale the first time 90% of the time, which may affect how critical their eye is on something like this.

Edited to add: other than color, the single most important thing to me was getting a stone with a "pleasing outline" as Dave puts it. Nobody can determine that from reading a GIA report other than the hint that the length/width provides. I think as you suggest that 1.55-1.65 is just right, a little more or a little less still works well.

 

[valeria101]

It would be the size of the facets near that "bow-tie area" that, I feel, have the most impact on wether you see a big bow-tie effect or not. I guess some proportions dictate the size of those facets, but I doubt there is a strict relatioship between this and the stone's proportions and angles and so forth. Maybe the Ideal scope signature of the stone could help, and definitely those 3D models posted by GOG, but to guess by numbers, you would need them all, and a reasonable tool to model the stone. Asymetric as pears are, I see no way to concoct a simple rule of thumb for them!

Anyway... there doesn't seem to be any shortage of pear cuts, at least among PS listings. I bet one selected for brilliance can be made available, as NiceIce mentions

I guess this (LINK) kind of low-down tells more than one can with just one diamond at hand. And there are quite a few promising "sets of numbers" on a shorty PS search - definitely worth descending from cyberspace

 

[oldminer]

You really should not see as much bow tie effect in AGA 1 and 2 class pear shapes as in the 3 or 4 cut class stones. This is because a better cut diamond hides the bow tie better. It still is there as it is inherent in pears, ovals and marquise shaped stones, but it is less visible when your eye is busier with excellent brilliiancy, scintillation and intensity.

You should note that a bow tie is a dark, less brilliant zone. Some of it happens because the stone is not as totally symmetrical as a round stone. The crown and pavilion angles vary greatly (along with length and width variation) and this sets up areas of less intense light action.

Don't confuse cut grading ( the search for a pleasing shape, showing proper size, and durability) with grading that eliminates (hides) a bow tie. While they go hand in hand when a good cutter is working, not every single cutter is a great craftsman. Some just are told to get the most weight, or to make a certain sort of stone. Not every diamond cutting shop is run the same.

More than any other thing, a bow tie effect is part of certain fancy shapes. Hiding them effectively is the art and skill of the cutter. While it is a part of diamond grading, the discussion of bow tie, it is not any major issue in pricing or cut grading.....

I hope this adds to the discussion and to your understanding.

 

[elmo]

Dave, that's great info...thanks.

 

[researcher]

Thanks everyone for shedding a little more light on pears for me. And I thought my own search for a princess was difficult! Good thing we have a couple of months for this one!