Comparative pearl sizes-- how much difference does 1mm larger really make?

This truly was an inspiration, PD, and so, so useful for all of us. Whether we use numbers or imagery, it brings the point home!
I just found this post. It really does explain why my new 8mm strands feel so much heavier than my older 6mm strands. The weight difference really surprised me, but now it all makes sense.
Yes-- the 8mm pearl is 2.37 times as large as the 6mm pearl! Well over twice as large.
A question arose on Pricescope about why an 8-8.5mm stud feels so much heavier than a 7.5mm stud.

Besides the volume increase, there is the issue of torque. Torque is rotational force. The farther a weight is from the axis of rotation, the greater the rotational force it exerts. Larger studs, being spheres, protrude outward from the earlobe farther than smaller ones do. Any increase in pearl diameter increases the distance of the farthest-most part of the pearl from the axis of rotation (i.e. the earlobe) and therefore increases torque.

Gravity pulls downward on all studs, but the rotational force is greater when the stud protrudes farther out from the ear. This is why larger spherical studs are much more likely to sag.

Button shaped pearls that are the same weight as a spherical pearl won't sag as much because the rotational force is less. Simple physics.
Pearl Dreams, this chart has been up for a while, but it was so helpful after a recent purchase and decision to upgrade the pearl size. Thanks for the sticky.
I'm glad it helped you, moneymeister!

I also decided to move the thread from the Lowly Beaders Club to the Cultured Pearls forum, where it it more likely to be seen by the many visitors to Pearl-Guide.

Undoubtedly many people visit Pearl-Guide for the first time when they are considering buying pearls for themselves or for a gift, and what better time to learn that a small increase in millimeters of pearl diameter yields a large increase in the overall size of the pearl? Especially in the light of PSS (Pearl Shrinkage Syndrome)-- the fact that many of us want larger and larger pearls as time goes on. ;)
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Smart move.
1mm seems like such a small upgrade until you read this post. So glad I did.
Right! Visualize expanding any pearl by 1mm outward in all directions from the center, and it becomes clearer why 1mm has such an effect.
It's 1mm more all over.
Just seeing this now, thanks to Pattey's bump. Thanks P-D, this is an amazing reference!
Thanks SunSeeker.

Another reason to be aware of volume is that the larger the pearls in a necklace or bracelet, the snugger they will fit around the neck or wrist.

An 18" strand of 8mm pearls will fit looser than an 18" strand of 10mm pearls.

A 7" bracelet that fits comfortably when the pearls are 9-10mm may be uncomfortably snug when the pearls are 10-11mm. It may be well to get the bracelet made a tad longer, depending on your own wrist.
One mm seems small & insignificant difference until I compared 9.1mm gold studs against 10.1 mm tahitian studs.

I like 8 to 8.5mm for daily & anything over 10 mm for me would be huge

8.3mm white to 9.2mm gold


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I am not much on the science of pearls. I am a buyer/seller and have been for 49 years. How the size looks on the neck is the measure
of 7-8mm. When a person is viewing from 4-5 feet away 1mm is difficult or impossible to discern. 2mm is different. My dad always said if they are looking at reading distance from the neck the size difference is not on their mind.
I don't know, pearl-man. I feel like my 7-8mm strand just looks too small on me, but I don't feel that way about my 8-9mm strand.

Perhaps the 1mm difference is just critical at the point that the strand begins to feel too small. ;)
Now I understand why we won the space race. In my 45-50 years of seling pearls I never would have given that a thought. Not useful in the selling situation but an amazing explanation. Certainly partially explains why natural pearls have .6mm hole to cultured whish is usually .8mm to 1.0m. Selling by weight. Not Volume but related. SUPER !!!!!