What sort of pearl is this?

[triscodiscuit]

many of the pearls on this strand have a flat end, many with a white ring- what causes this?

 

[Pearl Dreams]

They are Chinese freshwaters. Perhaps the flat dull area was against the shell.

 

[Pearl Dreams]

It occurs to me that you may like to learn more about pearls by taking the Cultured Pearl Association's "Pearls As One" course. It's a great course-- full of videos, photos and a great Q&A section after each chapter.
This is the website: www.pearlsasone.org

I will message you a code to take the course for free.