Why do we use Diameter instead of Area to measure?

[Blueman33]

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On 9/27/2004 1:52:28 AM Garry H (Cut Nut) wrote:

All this seems great, but you have ignored my post about light return.

I didn't mean to ignore a post.

However let's include light return, I am all for that.

If we include light return and diameter we are not as straight forward as including light return diameter and area.

Because diameter is misleading due to it's one diminision.

Take the quarter and dime example. When you say 33% bigger diameter than a dime, most folks don'w immediately think 77% bigger!

I am not advocating ignoring ANYTHING.

Not ignoring light return, not ignoring diameter, not ignoring color......

simply that area is a more straight forward measurement for the size of a diamond, why not include it?

It will only benefit consumers.

 

[Blueman33]

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On 9/27/2004 11:27:14 AM fire&ice wrote:

Why - because it's the measurement used in the trade. and can be quantified from looking at the cert.

I'm not one to change the way diamonds have been viewed for centuries for proper math.
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Interesting argument. It's been done this way for centuries so let's not change.

Diamonds are not cut the same way they have been for centuries, nor graded the same way they have been for centuries.

Do you use the HCA?? NO YOU SHOULDN'T. This hasn't been used for centuries.

OHH...you are on-line. That's a change from centuries ago.

Drive a car? Have a t.v.? Get to vote?

Change can be good.

 

[Blueman33]

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On 9/23/2004 3:09:24 PM quaeritur wrote:

Personally, . With just an area measurement, while I could come up with some average diameter, it wouldn't tell me if I was looking at a round, ovalish or squoval diamond...

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I never suggested ELIMINATING the diameter measurement. You can use that to determmine out of round.

I TOTALLY agree that diameter is better for measuring out of round. I am not advocating that area is better for out of round measuremnts, but that it's more straight forward for describing the size of a round stone.

I never suggested ELIMINATING anything.

Just that area of the face of a round stone is more straight forward in describing it's size than diameter.

It's seems (not YOU in paricular) that everyone is just closed minded. From a premise designed to help consumers, I get all kinds of arguments that area isn't good for setting stones (no argument, not on premise), it doesn't tell out of round (no argument, not on premise), it's been done in diameter for centuries and someone doesn't like high school math (interesting argument).

No one however can give a legitimate argument that it will not help the average consumer tell the size of the face of a diamond in a more easily understood and straight forward manner than diameter which is misleading because it is one diminsional.

Geez. One day PriceScope or a vendor will decide, "what the heck, we'll help people with a more understandable measure of size, it will take very little effort we'll give people a clearer more understandable picture"

 

[Blueman33]

Blueman33,

You continue to deal in absolutes. This is where the problem comes in. You simply cannot assume that a round diamond is a perfect circle, this is not the case. If you removed all diamonds from being called round that were not perfect circles there would be more removed than left over. You cannot equate a circle with a round diamond by definition. What you seem to be suggesting is that the entire industry reclassify the 'shape(s)' of round diamonds. Additionally you seem to be missing Garry's point. Two round stones of equal/identical area and/or diameter can and will appear to face up as different sizes based upon light return. To be quite technical, you are seeng neither diameter nor area, you are seeing light return and many factors influence this. It is a matter of perception and not mathematical absolutes.

Although the proportions to which stones are cut, and set to a different degree, is based upon mathematical and scientific absolutes, the end results rarely mirror those absolutes. If they did, absolutely every stone would be cut exactly the same. Jewelry is an art and not a science.

Dave

NO, it's not 'all or nothing'. It's not that a diamond is slightly out of round so the whole industy must change. No.

It's simple. Area is a more straight forward measurement for a round diamond than diameter because it's two diminsional, not one.

This means that when a diamond is so far out of round it is not classified as round, which IMO means it's lop sided to the naked eye, but take whatever industry standard. I am NOT advocating that standards be changed.

Simply......well, you know.

Worried about out of round? look at diameter. Want to get a straight forward indication of face size? look at area.

jewelry isn't science it's art. So Gary, get your computer program off this site (that's kidding). No more brilliance scope reports, that's science. So is a Sarin.

I totally agree with WF, the problem is that poeple are scared of change.

The area measurement of a round diamond could only HELP people, not hurt them. So why are you guys so up tight?

HEY, I ALSO THINK THE HCA SHOULD BE INCLUDED ON A DIAMOND!!!!!

BUT THEN AGAIN THAT'S CHANGE!!!!! AND SCIENTIFIC CHANGE!!!!!!


----------------[/quote]

 

[fire&ice]

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On 9/27/2004 7:11:02 PM Blueman33 wrote:

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On 9/27/2004 11:27:14 AM fire&ice wrote:

Why - because it's the measurement used in the trade. and can be quantified from looking at the cert.

I'm not one to change the way diamonds have been viewed for centuries for proper math.
----------------

Interesting argument. It's been done this way for centuries so let's not change.

----

OH Grasshopper....the diamond trade is the same. With very few changes. The other stuff is social. This game truly follows no model.

And truly, it's an easy, recordable measurement to understand.


Now, ACA...... A Cup Above.....couldn't resit even though w/ current climate - hand slapped!

 

[Todd07]

from a marketing angle, I'm suprised DeBeers hasn't pushed this approach to sell larger rocks

Why buy a 5mm diamond when you can buy a 7mm and get at 96% increase in dazzle area. It already makes me feel better about paying exponentially more for my bigger diameter stone

Diameter/Diameter increase/Area increase

7mm / 40% / 96%
5mm / 0% / 0%

 

[quaeritur]

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On 9/22/2004 6:15:35 PM Blueman33 wrote:


NO ONE SEEMS TO MENTION THIS, BUT DIAMETER IS VERY MISLEADING because it is one diminional. I think we should use AREA, not diameter.

I'm sure there's some reason why AREA isn't used, but it's more clear to me.----------------

OK, Blueman33, this is a quote from the post that started it all. Despite your recent protestations that "I never suggested ELIMINATING the diameter measurement" and "I never suggested ELIMINATING anything," it seems to me that the reason folks responded as they did, myself included, is that you did, in fact, suggest exactly that

.

And, again, I don't see how the area measurement would be helpful for the average consumer, because I can't visualize it. Nor can I calculate diameter from it it without a handy dandy little electronic device called a calculator (or in my case, brain supplement). On the other hand, I can visualize diameter measurements without any extra gadgets

.

 

[Garry H (Cut Nut)]

Back to my favorite topic, is it the ...... or the ..... that counts?

Those of you who know me can fill in the blanks

I think this topic is not going anywhere folks.

 

[valeria101]

I am late on this thread... but I would still add my 0.2 knowing you can always skip it guys

This thread sounds to me like one more "size" questions. Too bad "size" is an abstract niun in English leaving each to figure out what is "size" in numbers. After all, once you have those two section length on the cert, once can figure out surface easily. Even if the reporting custom is different than you'd like, one can still look at surface for "size".

As measurements look on the cert, it is a bit tricky to compare size across shapes. But this is not easy anyway, because there is no exact math to help. This is a matter of visual perception after all.

At least to me, it seems that surface works well in shapes with identical crossections (rounds and squares and hexagons since these are out there). And then proportiosn also play their role for the rest. So, to each his own.

Only comparing milimeters on the cert may not be the best idea if you want to know if that princess o square emerald cut is "as big" as a certain round. And this is the usual situatioon, I would think.

Hope the pic below shows better what I mean:

 

[valeria101]

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On 9/28/2004 10:36:54 AM crankydave wrote:

Blueman33 wrote:

It is all a matter of what a person can visulize.

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I would just add that very few people I know are confortable "visualizing" numbers. Especially when they are not told how to do that.

"Size" can have any number of interpretations of gemetry, if it needs have one.

 

[boonerings]

Kinda all leads back to my original thought. Rather than introduce a new mid-level dimension that is hard for people to visualize like area that doesn't really tell the whole picture, why not introduce a dimension that is also not easy to visualize, but very accurately describes the actual volume of the stone, not just the area. Oh wait; they do have one already- it's called carat weight!

 

[valeria101]

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On 9/28/2004 12:16:34 PM boonerings wrote:



why not introduce a dimension that is also not easily to visualize, but very accurately describes the actual volume of the stone, not just the area. Oh wait; they do- it's called carat weight!

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Well, weight and volume are not the geratest clues to how much of your finger than dimaond is going to cover. Most ring settings do not allow to see much of the 3D shape of a precious stone - bar tension settings really. So... why even look for a general solution to this ? How often does one choose his favorite shape of stone for a solitaire based on which looks bigger? It's mostly rounds and squares anyway, right ?

Somewhere on this thread the "price per surface" got mentioned. Here's how these prices look like below.

I used this price/sqmm indicator to linearize a larger sample of quotes. Actually, prices are more consistent this way too - so, statistically, diamonds appear to be priced by size.

The sample contains emerald cut diamonds of same color and clarity by GIA's word. The results have been normalized for scaling.

 

[boonerings]

Very interesting chart. It probably makes sense from a cut standpoint. Diamonds that are too tall weigh more, but don't get as good a light return, so are not as valuable as they should be based on weight.

 

[Blueman33]

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On 9/27/2004 8:43:35 PM quaeritur wrote:

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On 9/22/2004 6:15:35 PM Blueman33 wrote:


NO ONE SEEMS TO MENTION THIS, BUT DIAMETER IS VERY MISLEADING because it is one diminional. I think we should use AREA, not diameter.

I'm sure there's some reason why AREA isn't used, but it's more clear to me.----------------

OK, Blueman33, this is a quote from the post that started it all. Despite your recent protestations that 'I never suggested ELIMINATING the diameter measurement' and 'I never suggested ELIMINATING anything,' it seems to me that the reason folks responded as they did, myself included, is that you did, in fact, suggest exactly that

.

NEVER SUGGESTED eliminating diameter. The quote is to use AREA for the SIZE of the FACE of a diamond, rather than DIAMETER. I AM SORRY YOU THOUGHT I WAS ELIMINATING DIAMETER, NOT MY INTENT.

MY INTENT IS TO USE AREA TO JUDGE THE SIZE OF A ROUND DIAMOND, USE COLOR TO JUDGE THE COLOR, USE THE HCE TO JUDGE LIGHT RETURN, USE DIAMETER TO JUDGE OUT OF ROUND, USE WHATEVER YOU WANT.

NEVER SUGGESTED ELIMINATING DIAMETER, BUT USING AREA INSTEAD OF DIAMETER AS A MEASUREMENT OR SIZE........

And, again, I don't see how the area measurement would be helpful for the average consumer, because I can't visualize it. Nor can I calculate diameter from it it without a handy dandy little electronic device called a calculator (or in my case, brain supplement). On the other hand, I can visualize diameter measurements without any extra gadgets

.----------------

OK, SO you can't. MANy people can. Just as the person above likes knowing the size of a diamond has 96% more pizazz area! Area is more straight forward because the diamond is a circle not a line.

As far as calculators are concerned, I am suggesting that the information be provided, so you will not have to calculate. Right on the PS info they could put an easy model to type in two round stones and compare their size.

Personally, I think AREA, HCA, and a IDEAL scope image would all be nice information on a diamond. When I go to a website and they have MORE info, I like it better.

I think this would help consumers. And again, I never meant to eliminate the posting of diameter, just that area is a better measurement because it's two diminisional.

Right now, the major size measurement for the guy off the street, knowing very little, is carat size, which is weight. I think both diameter and area are better than carat size.

Cheers,
Blueman

 

[Blueman33]

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On 9/28/2004 12:05:14 PM valeria101 wrote:


I am late on this thread... but I would still add my 0.2 knowing you can always skip it guys

This thread sounds to me like one more 'size' questions. Too bad 'size' is an abstract niun in English leaving each to figure out what is 'size' in numbers. After all, once you have those two section length on the cert, once can figure out surface easily. Even if the reporting custom is different than you'd like, one can still look at surface for 'size'.

As measurements look on the cert, it is a bit tricky to compare size across shapes. But this is not easy anyway, because there is no exact math to help. This is a matter of visual perception after all.

At least to me, it seems that surface works well in shapes with identical crossections (rounds and squares and hexagons since these are out there). And then proportiosn also play their role for the rest. So, to each his own.

Only comparing milimeters on the cert may not be the best idea if you want to know if that princess o square emerald cut is 'as big' as a certain round. And this is the usual situatioon, I would think.

Hope the pic below shows better what I mean:


I like your illustrations. They are not on the subject exactly, but they are appreciated. Val, could you get two circles, one larger than the other on top of each other, together on one edge?

This was basically my point. Take a dime and take a quarter. You can place them side by side or one on top the other meeting on one edge. Heck you can spin them on the table!

When I tell you the quarter is 33% larger diameter, most people look at the difference between the two coins and think.......that's all???

Because the diameter is only one diminsional. The quarter is actually 77% bigger.

I am simply stating that for the average person, especially comparing two stones, area is less misleading and more straight forward since the face of a round stone isn't a line, like diameter.


The above DeBeers comment is in agreement. 40% diameter increase gets you a whole lot more than a 40% bigger diamond.

I think Area is a good measurement to include on a diamond.

More information the better IMO.

 

[quaeritur]

I would appreciate it if you could stop yelling.

OK, let me get this straight. When you say (and I quote again)

"I think we should use AREA, not diameter"

you don't mean get rid of diameter in favor of area???

Sorry, but I think what you actually said means eliminate diameter. Maybe that's not what you meant, but it is what you said.

As for area being better than carat weight... well, if you say that two dimensions are better than one, then by the same logic, three dimensions ought to be better than two.

Anyway, I'm happy to agree to disagree on this. You're more than entitled to your own opinion, but beating others over the head with it doesn't make you right either, and it becomes tiresome after a while

 

[Blueman33]

Slightly off topic:

Carat wieght is really scary. You guys are on top of the whole thing, but what about Joe Blow????.

Joe Blow can be sold carat weight over everything! Not just over the face size whether measured by area or diameter, but over cut, color, clarity as well.

I went to BM store here and EVERY stone looked great due to the intense lights. Most stones were SI2, not a loup to be seen in the place, and no certs.

Under those lights you couldn't see a pepper corn right under the table!

A big successful beautiful store no less.

And the first thing I heard, "What size stone are you looking for?"

It was scary..................

 

[Blueman33]

I would just add that very few people I know are confortable 'visualizing' numbers. Especially when they are not told how to do that.

'Size' can have any number of interpretations of gemetry, if it needs have one.

It is my opinion that however hard to visualize size, it is more straight forward to be factual when describing two stones.

So a quarter is in fact 77% bigger than a dime, not 33% bigger. The diameter being 33% bigger isn't stating that IS the size of the diamond, but for the average person they tend to take that measurement (since that's all they have) and use it.

Area is easier to visualize when comparing two stones. That is why you see my points are....."quater is 77% rather than 33% bigger than dime", rather than " a quarter is 452 sq. mm's".

Simply saying a single stone is 38 sq mm on the face, isn't as intuitive as using area in a comparison of two stones. I agree that would take some getting used to.

On a single stone, diameter is easier to visualize since you can take a ruler and count the mm's and visualize how big it is. 7mm diameter stone rather than 38 sq mm stone.

Thank you all for your consideration of my point.

 

[aljdewey]

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On 9/27/2004 7:11:02 PM Blueman33 wrote:

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On 9/27/2004 11:27:14 AM fire&ice wrote:

Why - because it's the measurement used in the trade. and can be quantified from looking at the cert.

I'm not one to change the way diamonds have been viewed for centuries for proper math.
----------------

Interesting argument. It's been done this way for centuries so let's not change.

Diamonds are not cut the same way they have been for centuries, nor graded the same way they have been for centuries.

Do you use the HCA?? NO YOU SHOULDN'T. This hasn't been used for centuries.

OHH...you are on-line. That's a change from centuries ago.

Drive a car? Have a t.v.? Get to vote?

Change can be good.----------------

Yes, but only if the change is *meaningful* to its audience.

The advent of the car meant people could get someplace faster...which was desired. The advent of TV meant they could get information faster/be entertained in their own homes.....convenience, which was desired. Get to vote.....input into the process that ultimately affects people...which was desired.

Unless the change improves and adds desired information, it's not helpful and it's a waste of time.

FYI, change can also be BAD, too. When I was a child, kids could trick-or-treat in groups with no parent present and do so safely. The advent of being online also means children can be lured into danger by unscrupulous people.

Change for the better is productive. Change for the sake of change isn't.

 

[aljdewey]

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On 9/28/2004 10:36:54 AM crankydave wrote:

Blueman33 wrote:

Area may be more straight forward to you but it is not to most people. If you doubt this conduct a survey or a poll and here is why...

It is all a matter of what a person can visulize. If you tell a person that a particular anything is 6mm in diameter or 1 inch in diameter or 1 meter in diameter or 1 yard in diameter they can visualize it. They know how much it is. They can bring an image to mind from that one dimention alone. They can equate a size from that dimention.

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This is a great point, Dave; people use the method they are most familiar with/comfortable.

Gaining acceptance for a new method is also hard because so many other models use length/width dimensions, so that's what we comfortable thinking in.

Have you ever noticed that house listings express room dimensions this way: 11 x 19. Why don't they list area - 209 sq ft? Because it's not as informative as 11 x 19.

I'm shopping for a house right now. One of the important criteria to me is having a large living room (because we entertain quite a few people at the holidays). The sq. ft of an 11 x 19 LR is 209; the area of 14 x 15 LR is 210. Very little difference, but I'd reject the 11 x 19 house. I don't want long and skinny....I want spacious.

If you told me the area of the LR was 209 sq ft, that wouldn't give me enough information.

I guess the best summary, Blue, is that *you* individually would find that information helpful. I, on the other hand, would not, and it would be useless to me. Difference of opinion.

Unless the market clamors for this information, I don't think it will happen.

 

[Mara]

I agree that it's very hard to visualize area, whereas with mm in diameter, while I was shopping, I could take a ruler, and literally draw out my stone to see what it looked like in person. This was hugely helpful in determining size that I felt comfortable with. Sure I went into stores and tried a bunch of diamonds and rings on. But while sitting on Pscope and reading about stones, a ruler, pen and paper spoke more to me than any big time calculation did. In the end it's about how it's going to look on your finger from the top down, which is diameter.




Lastly, I can see a .10mm difference in stones around 1.25c each. I don't know if I could see .10mm in a 3c stone, but I would venture to say that I am more around 10% diameter difference to really see it...instead of the 20% that was noted.




Blue...when you respond to other posts and quote people, try to differentiate your posts with a BOLD or a different color, it's very hard to determine what is going on.

 

[fire&ice]

Am I the only one that thinks this is the most insane thread?

Why not change carat weight to pounds?

 

[noobie]

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On 9/29/2004 10:30:55 AM fire&ice wrote:





Am I the only one that thinks this is the most insane thread?

Why not change carat weight to pounds?
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No, that's why I have not commented till now. Why not sell lumber by area instead of by dimesions? Instead of buying 2x4s we'll buy 8 square inches. (Yes, I know a 2x4 is not 2x4; it was only an illustration)

 

[boonerings]

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On 9/29/2004 10:30:55 AM fire&ice wrote:

Why not change carat weight to pounds?----------------

Because you'd have to specify Avoirdupois or Troy.