Diamond advice needed, please...

Hello all,

I have an opportunity to buy the following stone:

Princess Cut
GIA Cert
VS1
D color
Table 68
Depth 68
Girdle t (thin?)
Cutlet: none
Flouresence: none
Polish: VG
Symm: EX
5.66 x 5.65 x 3.84

.....for $5,700

A comparable diamond at bluenile.com costs $7,500.

So, why is there such a price difference? The stone for $5,700 maybe
has a terrible crown height?

One more question, would you trade off one grade in clarity for one
grade in color? For example, would you prefer to go from VS1 to VVS2,
at the same time going from D to E color? Which will have a larger
impact on appearance?

Thanks,

John

Forgot to mention that it is a 1.01 carat diamond.

On Wed, 02 Jun 2004 01:16:41 GMT, wrote:

Hello all,

I have an opportunity to buy the following stone:

Princess Cut
GIA Cert
VS1
D color
Table 68
Depth 68
Girdle t (thin?)
Cutlet: none
Flouresence: none
Polish: VG
Symm: EX
5.66 x 5.65 x 3.84

....for $5,700

A comparable diamond at bluenile.com costs $7,500.

So, why is there such a price difference? The stone for $5,700 maybe
has a terrible crown height?

One more question, would you trade off one grade in clarity for one
grade in color? For example, would you prefer to go from VS1 to VVS2,
at the same time going from D to E color? Which will have a larger
impact on appearance?

Thanks,

John

On Tue, 01 Jun 2004 18:16:40 -0700, in rec.crafts.jewelry wrote:

....for $5,700

A comparable diamond at bluenile.com costs $7,500.

So, why is there such a price difference? The stone for $5,700 maybe
has a terrible crown height?

Who knows. The GIA cert doesn't actually give you quite enough info to
properly evaluate the cut of the stone, so yes, if the pavilion is deep and the
crown too shallow, or some other factor makes one stone more attractive than
the other, perhaps it's worth the price difference.

But you're also forgetting that diamonds don't come with suggested list prices
that are uniform across the industry. Competition tends to make the true
wholesale market (to which you likely do NOT have access, despite the claims of
man discount sellers) somewhat predictable, with only modest variance from one
dealer to another. But as you note slight differences in cutting can make a
distinct difference in the appearance of the stone, and of course, the price
too.

And don't forget that any retailer can use whatever markup their business model
needs in order to be profitable. A diamond purchased from a small back office
jewelry shop where the jeweler had the stone sent "on memo" from his supplier,
and which he won't have to pay for until after you've paid him, will not
require the same retail markup as the same stone from a high rent store where
the stone is already bought and paid for in inventory, and perhaps already in
an expensive mounting. The differences in markup can be profound, as in the
difference between perhaps a ten or fifteen percent markup (very low. It's
rather hard to find that many jewelers willing to sell for that small a margin,
but some exist, especially on the internet, or in those small back offices...)
to a retail price of sometimes three times the wholesale cost, even for costly
diamonds. It all depends on the nature of the business selling the stone. It
does not automatically mean the more costly store is cheating anyone or the
like. It just means that what they're doing requires a higher profit margin
per sale in order for the business to remain profitable. In short, blue Nile
sells a lot of diamonds. But who says they're automatically the cheapest? All
it takes is someone willing to sell for less. Perhaps it's a stone that's been
in someone's inventory for a while. Perhaps they just got a better deal from
their wholesaler.


One more question, would you trade off one grade in clarity for one
grade in color? For example, would you prefer to go from VS1 to VVS2,
at the same time going from D to E color? Which will have a larger
impact on appearance?

The color will make a difference in appearance. The clarity grade differnce
you site is not visible to the naked eye. you'd need a good loupe, or
microscope, to see the difference. That grade difference is not one of
appearacne, it's more one of rarity, fueled by the odd concept that people
want some sort of perfection. I say it's an odd concept, since there really is
no such thing as absolute perfection in natural diamonds. At some level, there
is always something, somewhere, that is imperfect. maybe it's the internal
clarity, maybe it'd something else. But the notion that one needs exceedingly
clear diamonds for them to be worth buying is silly. It makes sense only in
the context of the percieved value, not the beauty of the stone. Indeed,
inclusions in diamond are there as natural events, the product of the stones
origin. Some inclusions may be actually quite interesting. All of them are
simply part of the natural nature of the stone, and inclusions in a stone can
be thought of as making that stone unique, unlike all others of the same grade.

On the other hand, it should also be pointed out that the difference between a
D color and an E color is not likely something a customer's eye will see
either. The three top grades in color (D,E,F) are more slight differences in
transparency, than anything else, and to judge them accurately, precise viewing
conditions are needed, not to mention a trained eye. Once you set the stone,
in normal viewing postion in jewelry, even your jeweler would probably not be
able to tell the difference with certainty.

if you want a characteristic that makes a big difference in appearance, look
closely at the cutting. The degree of polish, and the proportions of the stone
play an enormous amount in how the stone looks. Most princess cuts tend to be
cut with table sizes that are too large for real optical efficiency. If you
can find one with better proportions, ie decent crown angles and an smaller
table, even though this may make the stone appear slightly smaller in width and
height, you'll find it will give it dramatically more life and 'zing". This,
unfortunatly, is something that is very hard to judge from just a GIA cert.
With many diamonds, you can really only make a final decision on cutting
quality when you actually see the stone.

Peter Rowe

Diamonds are not much different than most consumer items in that they
are bought and sold every day for wide ranges in price. If you were
shopping for - say - a 2001 Honda Accord you might find the same level
of difference in very similar cars. If you want a shock in regards to
price differences, take that stone to a pawnshop and see what they offer
for it.

Carl
1 Lucky Texan


wrote:
Hello all,

I have an opportunity to buy the following stone:

Princess Cut
GIA Cert
VS1
D color
Table 68
Depth 68
Girdle t (thin?)
Cutlet: none
Flouresence: none
Polish: VG
Symm: EX
5.66 x 5.65 x 3.84

....for $5,700

A comparable diamond at bluenile.com costs $7,500.

So, why is there such a price difference? The stone for $5,700 maybe
has a terrible crown height?

One more question, would you trade off one grade in clarity for one
grade in color? For example, would you prefer to go from VS1 to VVS2,
at the same time going from D to E color? Which will have a larger
impact on appearance?

Thanks,

John


--
to reply, change ( .not) to ( .net)

On Wed, 02 Jun 2004 02:15:00 GMT, Peter W. Rowe
pwrowe@ixDOTnetcomDOTcom wrote:

On Tue, 01 Jun 2004 18:16:40 -0700, in rec.crafts.jewelry wrote:

....for $5,700

A comparable diamond at bluenile.com costs $7,500.

So, why is there such a price difference? The stone for $5,700 maybe
has a terrible crown height?

Who knows. The GIA cert doesn't actually give you quite enough info to
properly evaluate the cut of the stone, so yes, if the pavilion is deep and the
crown too shallow, or some other factor makes one stone more attractive than
the other, perhaps it's worth the price difference.

But you're also forgetting that diamonds don't come with suggested list prices
that are uniform across the industry. Competition tends to make the true
wholesale market (to which you likely do NOT have access, despite the claims of
man discount sellers) somewhat predictable, with only modest variance from one
dealer to another. But as you note slight differences in cutting can make a
distinct difference in the appearance of the stone, and of course, the price
too.

And don't forget that any retailer can use whatever markup their business model
needs in order to be profitable. A diamond purchased from a small back office
jewelry shop where the jeweler had the stone sent "on memo" from his supplier,
and which he won't have to pay for until after you've paid him, will not
require the same retail markup as the same stone from a high rent store where
the stone is already bought and paid for in inventory, and perhaps already in
an expensive mounting. The differences in markup can be profound, as in the
difference between perhaps a ten or fifteen percent markup (very low. It's
rather hard to find that many jewelers willing to sell for that small a margin,
but some exist, especially on the internet, or in those small back offices...)
to a retail price of sometimes three times the wholesale cost, even for costly
diamonds. It all depends on the nature of the business selling the stone. It
does not automatically mean the more costly store is cheating anyone or the
like. It just means that what they're doing requires a higher profit margin
per sale in order for the business to remain profitable. In short, blue Nile
sells a lot of diamonds. But who says they're automatically the cheapest? All
it takes is someone willing to sell for less. Perhaps it's a stone that's been
in someone's inventory for a while. Perhaps they just got a better deal from
their wholesaler.


One more question, would you trade off one grade in clarity for one
grade in color? For example, would you prefer to go from VS1 to VVS2,
at the same time going from D to E color? Which will have a larger
impact on appearance?

The color will make a difference in appearance. The clarity grade differnce
you site is not visible to the naked eye. you'd need a good loupe, or
microscope, to see the difference. That grade difference is not one of
appearacne, it's more one of rarity, fueled by the odd concept that people
want some sort of perfection. I say it's an odd concept, since there really is
no such thing as absolute perfection in natural diamonds. At some level, there
is always something, somewhere, that is imperfect. maybe it's the internal
clarity, maybe it'd something else. But the notion that one needs exceedingly
clear diamonds for them to be worth buying is silly. It makes sense only in
the context of the percieved value, not the beauty of the stone. Indeed,
inclusions in diamond are there as natural events, the product of the stones
origin. Some inclusions may be actually quite interesting. All of them are
simply part of the natural nature of the stone, and inclusions in a stone can
be thought of as making that stone unique, unlike all others of the same grade.

On the other hand, it should also be pointed out that the difference between a
D color and an E color is not likely something a customer's eye will see
either. The three top grades in color (D,E,F) are more slight differences in
transparency, than anything else, and to judge them accurately, precise viewing
conditions are needed, not to mention a trained eye. Once you set the stone,
in normal viewing postion in jewelry, even your jeweler would probably not be
able to tell the difference with certainty.

if you want a characteristic that makes a big difference in appearance, look
closely at the cutting. The degree of polish, and the proportions of the stone
play an enormous amount in how the stone looks. Most princess cuts tend to be
cut with table sizes that are too large for real optical efficiency. If you
can find one with better proportions, ie decent crown angles and an smaller
table, even though this may make the stone appear slightly smaller in width and
height, you'll find it will give it dramatically more life and 'zing". This,
unfortunatly, is something that is very hard to judge from just a GIA cert.
With many diamonds, you can really only make a final decision on cutting
quality when you actually see the stone.

Peter Rowe

Thank you for the detailed replay. Here is the Sarin data from the
stone: I cannot find any reliable reference to judge the various
angles and depths indicated, although the crown height seems a tad low
(but not too bad?). Anything seem way out of whack here?

1.01 carat
GIA
D
VS1
Depth 68
Table 68
G: Thin to Medium, Faceted
5.66 x 5.65 x 3.84
P: VG
S: EX
F: none

Sarin info:
Table: 3.87, 3.84, 3.89, 68.6
Crown Angle: 34.9, 34.4, 36.0
Crown Height: 0.46, 0.46, 0.46, 8.2%
Pavil Angle: 61.8, 60.0, 63.0
Pail Depth: 3.20, 3.20, 3.20, 56.7%
Girdle: 1.4%
Total Depth: 3.83, 67.9%

Thanks,

John

On Wed, 02 Jun 2004 19:01:08 -0700, in rec.crafts.jewelry wrote:


Thank you for the detailed replay. Here is the Sarin data from the
stone: I cannot find any reliable reference to judge the various
angles and depths indicated, although the crown height seems a tad low
(but not too bad?). Anything seem way out of whack here?

1.01 carat
GIA
D
VS1
Depth 68
Table 68
G: Thin to Medium, Faceted
5.66 x 5.65 x 3.84
P: VG
S: EX
F: none

Sarin info:
Table: 3.87, 3.84, 3.89, 68.6
Crown Angle: 34.9, 34.4, 36.0
Crown Height: 0.46, 0.46, 0.46, 8.2%
Pavil Angle: 61.8, 60.0, 63.0
Pail Depth: 3.20, 3.20, 3.20, 56.7%
Girdle: 1.4%
Total Depth: 3.83, 67.9%

The Sarin data merely shows the more precise raw data from which the GIA
figures are computed, of course. Those more exacting numbers may be useful
for identification, but normally, the larger amount of data isn't of much use
in visualizing what the stone will look like, with the notable exception of the
fact that now we've got the pavilion and crown ANGLES. in both the pavilion
and the crown, the actual facet angles are what's important, not the depth. In
the case of the pavilion, the depth and angles are dependant on each other, and
in round stones, at least, it's not hard to derive one from the other. But the
crown is different, and more complex to state. While the charts will tell you
that the tolkowski ideal cut proportions for a round stone dictate about a 16
percent crown height, that only applies when the table is in the 53 to 56
percent range as well. If the table is wider, then the crown will be lower,
even when the angles remain at the optimum, and as i said, the optics of the
crown depend on those angles, in relation to the table size, not the absolute
crown height. In this case, your crown angles are listed as 34.4 to 36, which
is pretty much right where they should be. In a round stone, the ideal is
about a 34.5 degree crown angle. That angle is important because with a lower
angle, dispersion (or fire, as it's also called) is quickly reduced through the
crown facets, while if much higher, too much light starts to be refracted out
to the sides, instead of back to the viewer, as well as some odd effects
starting to take place with the way various parts of the stone refract, making
the appearance change for the worse. The table, on the other hand, is more
efficient at simply letting light into the stone, so a larger table results in
a stone with greater overall reflectivity, (called brilliance). But as the
table gets larger, the overall area of the crown facets gets smaller, and even
with the right angles, the amount of area available to give you dispersion
(those spectral colored flashes of light, which as I said, is also called
"fire" in a diamond) gets less and less. The balance of table size to the
crown facet area is chosen as that ratio where there is still mostly optimized
brilliance, plus optimized fire. That, unfortunately, is a rather subjective
choice, as to just what is the prettiest. Plus, as the crown height gets
higher with a smaller table, then more of the weight of a stone goes into the
vertical dimension, making the stone appear smaller. So the trade offs are
that with an ideal cut stone, you've optimized all properties for the total
area of the stone. With the wider table on the so called "spread" stones,
there will still be lots of brilliance, but less fire, and the overly large
table also results in less of that sense of "movement" as reflections shift
around, when you move the stone or your viewing angle. (a property called
scintillation). However, the trade for the reduced fire and scintillation of a
spread stone is a stone that appears wider and larger for the same weight, and
often it will have a somewhat lower price per carat as well, since weight
retention from the rough is increased (meaning you can cut that one carat
spread stone from a smaller rough diamond than would be require to cut a one
carat ideal cut diamond.

Have I lost you yet? Hope not. Sorry for the long paragraph. But that, in
essence, is the short course on the optics of diamond crowns.

The pavilion is simpler. It's sole role is to act as a total reflector, and
that is totally a function of the pavilion angles. or the pavilion depth,
which measures, in essence, the same thing, since the stone comes to a point (
the culet) leaving us with the simple math of the triangular cross section of
the pavilion.

At least that's the case with fully symmetrical round stones. Easy to analyse.
However, with fancy shapes, things get (didn't you know it) more complex. The
angles of the pavilion still come to the point of the culet, but with non-round
stones, usually there will be several different pavilion angles, depending on
where you measure the angle from. Convention states that pavilion angles are
specified from the width, or from the middle of a side in stones like princess
cuts. Normally, this works, as the facets are normally angled, in most cuts,
straight from the girdle towards the culet. But princess cuts are a special
case. If you look at the pavilion of a princess cut, you'll find that the
square sides are separate, often much steeper and not very large facets that
define the shape just below the girdle, while the majority of the pavilion
facets radiate from the points of the stones. What is actually happening is
that the light reflection paths in princess cuts don't go across the length or
width of the stone so much as they go corner to corner. The important angles
for the pavilions of princess cuts are the angles to the culet as measured from
the corners. Unfortunately, that's not what gemological conventions dictate,
so we're left with figures like 60 degree pavilion angles and 56 percent depth,
which in a round stone (which should be around 43 percent depth) , would be
virtually black, unreflective, and lifeless. And I know of no simple chart or
conversion to give me an idea of just what the specified pavilion angles should
be for an ideal princess when stated as the side to side, or lengthwise
measurement that you've got. So one is left with what actually is a simpler
and easier method, visual examination. You just look at the stone and examine
the reflection in the pavilion, of the table facet. It looks like a darker
zone directly in the center of the stone. Ideally, it should be about a third
the width of the table itself. Some people might know whether you Sarin data
reflects an ideal pavilion angle for a princess cut, but i'm afraid I don't.

So the main thing I can tell you is that most of the data appears to look about
right, though i can't judge the pavilion. The crown is decidedly spread, with
a wider and ideal table, but the crown angles are good. Note, however, that
the majority of princess cuts are cut this way. Smaller tables on princess
cuts can be had, but are a lot harder to find than with rounds, cost more, and
some people, used to the "standard" look of the proportions of most princess
cuts, might feel a better cut looks slightly lumpy, or high in the crown. I
happen to disagree, but some folks prefer that shape with the wider table.

Hope that's of use.

Peter