Pear Shaped Diamond Question.....

[FB.]

I am currently awaiting more detailed information on a 1.13ct pear shaped diamond that has taken my fancy. The info is likely to be emailed to me early next week.

In the meantime, since I have 3-5 days of waiting (the diamond has kindly been "reserved" while I await the info to make my decision), I am wondering just how much I can "guesstimate" about the diamond's general performance and be better prepared to make a decision on it.

Here is the info that I have from the GIA cert:

Dimensions: 8.63 x 6.05 x 3.77mm.
Table: 55%.
Depth: 62.3%.
Girdle: Thin to very thick (faceted).
Polish: Very good.
Symmetry: Good.


From my quick estimations and trying to envisage the combinations for actual crown/pavilion proportions that might result from the known proportions stated on the cert (guesses from depth, table, girdle thickness etc), I can't see many combinations that would result in a poor stone.

My thinking is along the lines of:
The weight is well above 1ct, so the cutter had the option to make a better proportioned stone, without losing the magic 1ct level.
The small-ish table suggests the likelihood of a slightly steep crown angle and a slightly higher table %.
If the crown angle is slightly steep, then the 62.3% total depth and slightly-thick-ish girdle may well result in a nicely-angled pavilion that compliments the crown.

While I eagerly await more detailed information next week, what do you think? Can you envisage likely combinations of poor proportions?

Thanks,
FB

 

[Richard Sherwood]

Date: 7/31/2009 5:19:10 PM
Author:FB.

While I eagerly await more detailed information next week, what do you think? Can you envisage likely combinations of poor proportions?

There''s always the possibility of a shallow crown / deep pavilion or deep crown / shallow pavilion combination, although that''s not probably not likely.

 

[FB.]

More detailed info on this diamond (but no images available).....

Table: 55%
Crown angle 33.5'
Depth: 62.3%
Pavilion angle: 41.8'
Girdle: thin to very thick
Length: 8.63
Width: 6.05
Depth: 3.77
The "corners" of the rounded end of the stone have about 10% greater radius than the width (about 3.3mm from centre-to-edge)

My gut feeling says that the angles are not too bad, since they are slightly steep for a round, but the angles of a pear will get shallower the further from the sides the measurements are taken.

41.8 pavilion / 33.5 crown is not great, but take a couple of degrees off (for the increasing slope as the stone lengthens) and the angles start to look good.

Is it worth getting this diamond shipped to me for visual inspection, or am I likely to be wasting my time?

Honest opinions appreciated. I'd rather reject a good stone than waste my time handling a bad one.

Thanks
FB

 

[Lorelei]

Is there any possibility they could send you a photo of this pear? These shapes are very difficult to analyze by numbers, at best all you get is a chalk outline of the stone, so a photograph would be a tremendous help.

 

[FB.]

Pictures are unlikely.
It seems as if the preferred way forward is for me to take delivery of the stone and return if I''m not happy.

If there''s a glaring anomaly in the numbers that one of the diamond number-crunchers can anticipate, it would save me the time and hassle of taking delivery, analysing and then having to arrange return of the stone if it wasn''t good enough.

I''m just hoping for some "best guesses" from experienced diamond people.

Looking at AGA''s guidelines for a top-grade pear (grade 1A), they quote:

Table: 55-60% (55% - CHECK!)
Crown height: 12-15% (33.5'' crown angle suggests a crown height just under 15% - CHECK!)
Girdle thickness: FAILED - but thin to very thick averages as about medium 4%, so apart from the wide variaiton in girdle, the mid-point seems OK.
Depth: 59-63% (62.3% - CHECK!)

So, apart form the wide variation in girdle thickness, it would rate as a cut grade of 1A on AGA''s charts.

FB

 

[tyty333]

Fancy cuts can not really be "picked" by the numbers like rounds. For me personally, I would never order a
pear without a picture or someone's opinion on it that I trusted. There is a chance it could be a pretty stone
but with all the not-so-pretty pears out there it seems like the chance is higher that it is not. Do you know
anything about how the bow-tie is in this stone? That determines to a great extent the character of the
stone. Also, what do the shoulders look like (on the rounded in). They could be nice and rounded or...
they could be square and not so attractive.

If I were you, I would stick with a vendor who has pictures or with someone who could bring a stone in to
review it for you at no cost to you.

Like Lorelei said...numbers give you the chalk outline. Might or might not be a pretty stone.


EDIT - if you could give us an idea of what you are looking to spend (and any details we need to know)
we might be able to point you towards some.

 

[tyty333]

Have you seen this shape selector tool...gives you the look of the stone using the height/width.
(also fun to play with...select the pear shape at the top)

http://www.gemappraisers.com/shapePickerNew.asp

Your stone has a 1.43 ratio (which makes it a little more on the shorter/chubby side - like mine).
AGS likes them in the 1.5 to 1.75 range but thats not that important to me if that is the look you
like.

 

[FB.]

OK, I'll come clean.....

I am looking for something unusual. Cost does not matter too much.

The stone described above is "special" because..........

Cert:

Weight: 1.13ct
Colour: D
Clarity: VS (with only one small feather, one small cloud and one small crystal - and nothing located under the table).

The special bit is that it has extreme blue fluorescence and I have it in writing that it does not go hazy/milky/oily.......

...................

The likelihood of finding one similar would seem to be quite low. Therefore, it would appear to be a case of "take it or leave it".

 

[FB.]

I''m almost tempted to get it and lose up to 0.13ct in some kind of re-cut, if necessary.

 

[Rockdiamond]

Hi FB,
Congrats!

I agree with tyty333 and Lorelei
Personally, I''d hate to buy something like this without at least some photos.

IMO the cut charts are extremely misleading as they classify things in "cut grade classes" which are prejudicial, and don''t actually indicate which stone you may prefer in real life.
NO expert can give yo a meaningful assessment based on the stats- especially in a pear shape.
Even a tool designed to show what different ratios look like won''t be able to capture the subtle differences between stones.


I would strongly advise against buying the stone to have it re-cut.

If you are comfortable using the money back guarantee to look at the stone, you should be fine.
Trust your eyes!

 

[FB.]

tyty

Using the GA pear tool on the link that you supplied, my best-guess from the info that I have, would seem to be with the following inputs:

L:W 1.43
Bulge factor (upper) +5%
Bulge factor (lower) -15%

 

[Lorelei]

Date: 8/3/2009 4:18:32 PM
Author: FB.
I'm almost tempted to get it and lose up to 0.13ct in some kind of re-cut, if necessary.

Buy the diamond if you wish and make sure you have a solid return policy so you can inspect it, but do not buy it with the thought of a recut or tweak, only an expert cutter could give you any kind of estimates on recutting and potential weight loss, it isn't something that the layman can calculate with any accuracy and an expert would need to evaluate the diamond in person to give you any meaningful advice. Also recutting is not without risk, you could lose the whole diamond if it broke or shattered at the wheel, this isn't common but it does happen. I don't think you will find any expert here will advise you to buy the diamond just going by numbers without either seeing it in person or at least having photographs and preferably ASET. Numbers have their place to eliminate the diamonds which aren't so likely to be well cut, once you do that then it must come down to images or your own eyes.

 

[FB.]

Lorelei

You mention ".....numbers have their place to eliminate the dimaonds which aren't.....well cut......."

But is it reasonable to say that those numbers justify further inspection, since they generally fall into AGA's highest cut grade (apart from the girdle)?

I trust the seller, but I suspect that if I reject the stone, I might either have to pay for the shipping both ways (probably not cheap - I think that the stone is not in my country at present), or be obliged to buy something else from them. Plus the time, effort and hassle involved in returning an item.

 

[Lorelei]

Date: 8/3/2009 4:48:00 PM
Author: FB.
Lorelei

You mention '.....numbers have their place to eliminate the dimaonds which aren't.....well cut.......'

But is it reasonable to say that those numbers justify further inspection, since they generally fall into AGA's highest cut grade (apart from the girdle)?

I trust the seller, but I suspect that if I reject the stone, I might either have to pay for the shipping both ways (probably not cheap - I think that the stone is not in my country at present), or be obliged to buy something else from them. Plus the time, effort and hassle involved in returning an item.

Yes, the numbers are useful to eliminate those which aren't likely to be well cut, so going by the AGA cut class charts this one does appear to be worth further investigation. The girdle might only be very thick on the tip for protection as an example, so it could be perfectly acceptable, ask the vendor if you trust them to tell you what part of the girdle is in fact very thick.

Make sure the seller has a solid and generous return policy that gives you plenty of time to inspect the diamond and return if needed ( with a full refund - no exchanges), also the shipping might not be too expensive. Or what you could do is to arrange for the diamond to be sent to an appraiser if you have one closeby where you could view it, they could take care of returning the diamond for you if you decided against it.

 

[FB.]

Update........

Diamond has been received, approved and is now mounted in a solitaire ring. Needless to say; it''s a very nice diamond.

8.8 x 6.1 x 3.8 mm
L:W 1.46
Weight: 1.13ct
Colour: D
Clarity: VS1
Table: 55%
Depth: 62.3%
Crown angle: 33.5''
Pavilion angle: 41.8''
Girdle: thin to very thick


One of the inclusions is hidden under a prong. Another is underneath the stone. The last one (a tiny black crystal with a tiny cloud adjacent) can only be seen with a loupe through one of the small facets.
As noted above, the girdle thickness is quite variable (htin to very thick) and the reason would appear to be because the girdle is not symmetrical - but it''s only noticeable with a loupe.

If it was scored along similar lines to how the HCA grades the round diamonds that my Mrs owns, I''d guess that it''d score about 2-3, with the individual breakdown probably approximating to:

Light return: Good
Fire: Excellent
Scintillation: Very Good
Spread: Very good

Fluorescence: Very strong lavender blue/lilac.
Bowtie: Very good - barely noticeable at normal viewing distances.

In full (British) mid-day sun, the diamond darkens and turns a light lilac colour. Lots of fire flashes tend to mask much of the blue tint.
Outdoors, in light shade, the diamond has a more noticeable blue tint because there are no direct light sources to reflect or cause fire.
Standing at the back of a room, about twelve feet away from an open door, the diamond still has a slightly detectable lilac tint.

Putting this diamond beside an H or I colour in a dull room tends to exaggerate the yellow tint of the lower coloured diamonds to an alarming extent - presumably because of the blue colour being complementary to yellow and therefore the yellow suddenly becomes very prominent.
It has certainly seriously relegated the H-I colour stones that previously looked colourless when compared to D-F colour stones.

Maybe one day I''ll be able to do some good pictures. Some mediocre pictures will follow in a few minutes.......

 

[Amethyste]

OooooooOoooooooOOOO.. PECTUREZZZZZZZZZZZZZZZ!

 

[Lorelei]

Date: 8/13/2009 11:17:34 AM
Author: FB.
Update........

Diamond has been received, approved and is now mounted in a solitaire ring. Needless to say; it''s a very nice diamond.

So glad you are pleased with it!! Would love some pics too!

 

[tyty333]

I''m so glad it turned out to your liking! We would love to see pictures!!!! PLEAZE!!!

 

[FB.]

Help!
I keep getting a error messages. Does this forum have a picture blocker?

"..........Error Message
Unspecified error. Please report this error to the webmaster of this board. Thank you.

If you want more information about this error or would like to report this error to the administrator of this bulletin board, please contact the webmaster of this web site. We appologize for any inconvenience this might''ve caused you......"

 

[Amethyste]

they have to be less than 100KB - and try to name the file with something more complicated than pear1.jpg... it has to have an unique name...

 

[FB.]

How's this?
Picture taken around 16:15 BST in near-full, direct, late afternoon sunshine.

 

[FB.]

...and another....

 

[FB.]

.....and last picture.
Taken outdoors in the shade of a wall at 16:15 BST.
The stone still has a slight blue tint.

 

[Amethyste]

I can see the tint! I think you might need to set your camera to the little flower setting or whatever is on your cam so it can take more focused pictures, to show more details

 

[FB.]

Camera is set to "flower" but that''s as good as it gets. I''ll have another go shortly.......
The camera doesn''t like to focus closer than about 2ft.

 

[Lorelei]

Its FABULOUS, look at those blues.....Congratulations, you picked a winner!!!

 

[FB.]

I managed to take some better pictures.
Unfortunately, we have lots of cloud cover today but when the sun breaks through, I''ll try to get some good pictures of the blue glow.
UV index is expected to be "medium" today (in British terms) - when the sun comes out.

 

[FB.]

Try this:

 

[Lorelei]

It looks great, really love the shape too!

 

[FB.]

...and on the patio in hazy mid-day sun: