Millimeters and what the eye can tell....

[laurenk]

Hello! I'm wondering if anyone knows when the human eye can tell the difference between diamond sizes and when it's too close that the eye can't tell?

I've googled this but cannot find an answer.

For example - can one tell the difference between say a 6mm vs 6.5mm stone?

Or is there a point that is too small to notice?

I did read that .4mm can be distinguishable but I have no real
Idea.

I'm upgrading my princess 1.55ct (6.42 x 6.24) to an emerald cut 2.32ct (8.46 x 6.45) and wondering if I'll really Notice a big enough difference?

 

[UrsTx]

I personally can see a diff in size with a .2-.4mm change. I had a 8.04mm round diamond and upgraded to a 8.4x8.5mm cushion. The cushion looks bigger for sure!! Here is a pic I took of a 6.7mm round earring, my 8.04mm round, and the aforementioned cushion. I apologize that it's sideways (iphone/iPad pic).

 

[laurenk]

Great picture!!! I can definitely see a diference too!! I suppose it's not often diamonds are all lined up and the size difference is really obvious but I really want to feel I've had a big upgrade!!
Your diamonds are gorgeous!!

 

[Asscherhalo_lover]

If the diamonds are all the same shape and cut quality I can easily see the difference at around .2mm, it's trickier when they're different shapes.

 

[rimjaja]

setting plays a major role - the ring on top has a .93 stone, the one on the bottom is 1.9 ct. To me they don't look that far apart size wise. My hubby wears a .85 stone- yet it looks between these in size.

 

[baby monster]

I can tell the 0.5mm difference in increase for rounds. I upgraded my studs from 6.5mm to 7mm rounds and there's a noticeable difference. It might be more difficult with different shaped like going from princess to emerald. I plugged the dimensions of your stones into that other very helpful site and it comes up with increase of 29% in face up size. This is what the rendering looks like.

 

[laurenk]

Thanks everyone for your replies and pics! Baby monster that site is invaluable!! I just want to make sure I really feel a big difference - and it's worth the money to upgrade. Stone is same width just about as my princess but will be 2mm longer.... So it's an odd comparison.

 

[diamondseeker2006]

You can definitely see that much difference as the image above shows. (babymonster...I'd like to know what site that came from. Can you give me a hint?)

 

[laurenk]

Hi diamond seeker!! It's d i a m d b dot com
Hope that makes sense!!!! Compares all dimensions you wish to enter and you can change finger length, ring size, skin tone too!

 

[rimjaja]

Never mind. I got it figured out

 

[FightGravity]

It will definitely look bigger- as long as you are not going from a halo to a solitaire at the same time! - and be a lovely size!

If you want to increase coverage along the width, trapezoid side stones are beautiful with emerald centers.

 

[ihy138]

If they are loose, I can see a difference at about 0.5 mm or maybe a little less. If the stone is set, all bets are off for me.

 

[WinkHPD]

It really depends on the cut of the diamonds. I have a picture somewhere of two stones. One is a 0.80 ct and the other is a 1.02 ct. The 1.02ct MEASURES LARGER than the 0.80ct and looks about the same size when seen in jewelry store lighting, but when in even in a little bit less light looks much smaller than the 0.80 ct stone.

No time to take a new picture today, but let me go find the one I have and share it with you.



Here it is, taken many years ago. Just as relevant today as then, maybe more so, since so many cutters have gone to the exaggerated steep deep to add as much as 6% weight to their diamonds.

Wink

Oops, wrong picture. I will go look for the right one and post it if I can find it.

Bummer, I can not find it, but here is a photo from many years ago when I was an Eightstar dealer that shows exactly what I am trying to say. The diamond on the right actually measures bigger, but LOOKS smaller because of its inferior cutting. Cutting can make a HUGE difference in the apparent diameter of the diamond. This was published on Pricescope probably thirteen or fourteen years ago, Early in the "Cut Wars" days.

 

[Michael_E]

.1mm equals about .004 inches or about the thickness of one piece of copy paper....very hard to see. A couple of things which really makes a difference in how noticeable two stones of different sizes are is how close they are to each other and, as shown by rinjaja, what the stones are surrounded by. For earrings sets, in which each stone is on the opposite side of your head, it can be very hard to tell a .5mm difference, yet if you put them close together it is immediately obvious which stone is larger. As for the stones surroundings, well that's why halos are so popular...they make the center stone look a lot bigger.

 

[laurenk]

Thanks Wink for such a detailed description and for taking the time to find the pics and post! I agree that being well cut does make a diamond look bigger as its much more sparkly!

Im thinking of adding sidestones just need to think about it carefully....

I appreciate everyones feedback and comments. My princess is set, obviously, and when I had the loose emerald to compare, the emerald looked small, but I know Im not comparing apples with apples, and once set the emerald will be much bigger on my finger than the princess......