Curator reveals fascinating facts about pearls

[Caitlin]

This is a good place to put a duplicate photo with a link to the Nautilus thread. If someone posts such a pearl again, we can add that too.

[Miriam Reed]

Effisk,
Thanks for posting the excellent photos. They're very clear and are a good addition to the thread. Don't you wish you had a collection like that? I'm afraid I had to slow down and drag my limited French out of the recesses of my memory to read your quote, but I finally figured it out! As you say, he basically said the same thing as Strack. I remember thinking the first time I saw the diagrams in her book that they show the process in a very clear, easy to understand way. It was a good idea to reproduce them here.

[Mikeyy]

Kidney stones are pearls if you want to get technical....LOL

[Raisondetre]

Eww!!! Why did you have to say that?

[Valeria101]

Yuck, man....

besides, those don't call for epitelial cell seeds (comparing with the Strack drwings posted above) and it is quite debatable whether they have any protective function similar to that of pearls for mollusks.

Sorry for the gratuitous defense.... I just hope there's no comparison (wishful thinking, maybe...). Although, I can think of a couple things tht the mamal body does tat resemble the function of parls (i.e. protective coatings triggered by intrusions in some types of tissue - not usually mineralized though).

That aside...

The white pearl in these piectures reminds another, magnified, posted as a teaser HERE Do you have thee pictrues in larger format, 'effisk' ?

[effisk]

I'm afraid I don't have any hi-resolution pics of the ones above. Here's the nautilus one:


About the Strack book and its pictures, there's an illustration that describes a very suprizing (and debatable) process.
I don't have the book with me right now but I remember it's on page 126 or 126, pic #87.
Strack describes an object being expelled through the solid shell. How could such a thing happen? Once the shell is formed, the material is solid and its state cannot change.

I never took the time to ask Strack abouth this illustration. I briefly discussed it with H.Bari who found it surprizing too.

[Caitlin]

I recently read about that process, but I forget where, maybe Streeter.

He claims the outer shell is continuously worn away as layers of nacre are deposited on the inside. Otherwise the shells would get thicker and thicker. So a blister pearl that started out between the mantle and the shell will eventually be found coming through the outside of the shell.

I checked out the pages you indicated in Strack. It seems to be the same process So a worm that bores in from the outside who gets way inside the shell will eventually be expelled back through the outside.

I am holding this idea in a holding bag inside my brain until further info is obtained.

I brought this process up in another thread, but can't remember which one.

[knotty panda]

Kidney stones are pearls if you want to get technical....LOL

I'm not so sure of that. Where's the irritant?

[effisk]

He claims the outer shell is continuously worn away as layers of nacre are deposited on the inside. Otherwise the shells would get thicker and thicker. So a blister pearl that started out between the mantle and the shell will eventually be found coming through the outside of the shell.

Does the illustration show this on the Strack book? It just seemed that the irritant was migrating through the shell, but what you describe makes more sense. Thanks.

[Hanaleimom]

Thank you, effisk. The pictures are amazing. I like the shells too.