When can the eye determine a change in size?

[Blueman33]

If you have a RB diamond, when can the naked eye detect a size change?

Carats can be misleading. I realize a fat setting shrinks a diamond as a fat finger does, and brilliance helps a diamond, and cut makes diamonds have bigger or smaller diameters, but given all things equal, how much size change can be detected with the eye???

Let''s say a 1 carat RB is about 6.5 mm.

At the 1-1.5 carat level, based on the same cut, can you tell a 6.7 or .2 mm difference? or does it take .35 mm or .5 or what?

I can''t readily differentiate a 1.1 and 1.2 carat diamond, similarly cut.

I CAN see the difference in a .95 carat and a 1.24.

I am thinking I should do one of two things. Either choose a smaller diamond (like 1-1.04 carats) and skip the expense of 1.08-1.17 since I can barely tell the difference if at all......OR go for the 1.20-1.25 category, which is more expensive, but at least you can see the difference. I''m thinkin the 1.09-1.17 is sort of an inbetween that''s not a good choice for me, a wasteful ''no man''s land'' of carat weight.

Thank you for your opinions, ESPECIALLY if anyone has researched it and done analysis. u>.

 

[alexah]

I've read it on PS before that, generally speaking, the eye can detect a dif at about .2mms - there's a chart posted here

Btw, if you're considering going a bit larger, this 1.23 WF I VS2 might tempt ya a bit...?

 

[goldengirl]

In my experience....I can't tell the difference between a 1/3ct and a 1/2ct. These stones may have been .4 and .5, or .35 and .5--so either a .1 or .15 difference, I'm not sure, but they looked identical to me!

I COULD tell the difference between 1/4ct and 1/2ct, and side-by-side between 3/4c and 1c, but when she put the 3/4c on my finger I thought it was 1c. (Then again, I am a BAD judge of things like distance and weight.)

To be frank, she's not going to be comparing the diamond on her finger to the one .15c more in the case...so just buy what's in your budget and she'll love it!

 

[JohnQuixote]

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On 9/19/2004 3:44:44 PM alexah wrote:

I've read it on PS before that, generally speaking, the eye can detect a dif at about .2mms - there's a chart posted here



Btw, if you're considering going a bit larger, this 1.23 WF I VS2 might tempt ya a bit...?

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Blueman,

So glad you mentioned it...

"Cut is king! Cut is king! Cut is king!"

Thus, given precisely the same cut, the .2mm guideline is appropriate. Two caveats though: 1. Stones you compare will not typically be identical in cut. Therefore, rely on those particulars and not just a comparison of mm if you cannot actually see the diamonds next to each other with your own eyes.

2. Remember that the .2mm rule relates to un-mounted stones. Mounted, that slight visible difference diminishes.

As for your "splitting hairs" dilemma... (what goldengirl was alluding to)

Comparing well-cut diamonds head-to-head in-shop is different than seeing them in daily life... It is like shopping through many same-model Porsches together in the showroom with slightly different trim: When you see them at the same time the final decision is hair-splitting and excruciating, but in daily life people who see that caliber of car will say "Holy Moly! Nice Porsche!" ...And so it goes with well-cut, beautiful diamonds "all in a row."

 

[Julian]

Ah, how wise the above poster is.

Cut is king! All hail the cut!

I've noticed that as carat size increases, it's harder to discern tenths of a carat. I know that seems like an obvious thing to say -- but consider looking at a 3 carat diamond among others that weighed 3.15-3.2, even. After a while, I couldn't really tell the difference unless they were side by side.

 

[Blueman33]

John,

I had written 2 emails to WF.com and addressed it to Brian asking to pull a couple of stones for Monday so we can see if we can match me up with a rock.

I am customer who will be buying in the next two days if I can find the right match. I may take a little bit of time for the final decision, but whomever contacts me will only need to describe stones, not have to educate me, as the generous members of Pricescope have already done that for WF!

Please have Brian access his email pronto on Monday morning, or if Brian doesn't personally answer email, you or whomever can contact me. [email protected]


Thanks,
David

 

[alexah]

Sometimes the vendors are a bit slower answering e-mails than answering the phone

WF Telephone:
1-877-612-6770

Outside of U.S:
1-832-252-6770

 

[JohnQuixote]

David,

We will be in touch. Thank you for the heads-up. It's great that you have been able to benefit from the collective wisdom here: Further proof that this site performs valuable and necessary consumer advocacy.

Spread the word about Pricescope

 

[JohnQuixote]

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On 9/19/2004 6:10:54 PM alexah wrote:

Sometimes the vendors are a bit slower answering e-mails than answering the phone

WF Telephone:
1-877-612-6770
Outside of U.S:
1-832-252-6770----------------

Perhaps it's due to that constant ringing sound...

(Thank you Alexah)

 

[valeria101]

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On 9/19/2004 5:11:35 PM JohnQuixote wrote:

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2. Remember that the .2mm rule relates to un-mounted stones. Mounted, that slight visible difference diminishes.

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Glad to hear it for once

side by side, unset stones need about 5% difference in surface area to be told apart ever so slightly, IMO. I could not come with a better way to put this "into numbers".

If they are not symmetrical cuts (round or square) proportions or even the position of the stones definitely blurr small differences for good.

Once the stones are set alone and seen one by one, it takes about a milimeter to show some difference of 'presence' - somewhat less if I get to see the rings side by side.

This purely statistics though - as unemotional as it gets.

Highly brilliant diamonds and/or superb settings would always impress me - all more so knowing that savy jewelry shopping is no simple matter.

 

[bar01]

Wonderful Discussion! Good Information !

 

[Blueman33]

And of course when you are in .20 mm territory or in 8mm territory the .2 rule would be differenc.

One could easily see a difference in a .2 and .4 mm RB, since that's 100% bigger, and the difference in 8.0 mm and 8.2 mm is a mere 2.5% bigger,

in the 1 to 1.5 carat range, 5% is a more than .2 mm

Typical 1 carat is say 6.5mm. 5% is .325

So I grouped the things I'm looking at. 6.49 to 6.62 group 1, 6.67-6.87 group 2, 6.89-7.09 group 3. Based on my budget, i'll likely split the difference and get a nice 1.1 to 1.18 stone in group 2.