Are pearls removed naturally?

Skib2000

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Oct 9, 2012
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Are pearls ever removed naturally while in the water? I've read and seen them removed by different methods involving humans. But I am curious if they are removed without any aid of humans. Thank you.
 
Interesting question! But -please forgive me- I don't fully catch the meaning of it. Did you mean: if pearls can simply "fall out" of the oyster without Human intervention? The answer would be "YES". And this can happen to both cultured and natural pearls.

What happens is that many pearls can grow within a very thin (just cell-thick) "pearl-sac" that can sometimes just "burst like a ballon" and the pearl is then released into the shell cavity and eventually even expelled out of it. I have never witnessed this (hard to stay underwater 24/7) but I have had oysters with natural pearls in them...only to inspect them again and find the pearl missing (much to our pain).

Why does this happen? The size of the pearl matters (larger pearls are easier to expel=harder to keep in the sac), as well as environmental conditions: low food availability makes oysters become thinner and the sac can become much less resilient too.

Hope I answered your question.
 
I suddenly feel the need to learn scuba in the Sea of Cortez and give the sea floor a good looking-over. :)
 
I suddenly feel the need to learn scuba in the Sea of Cortez and give the sea floor a good looking-over. :)


Haha, a dive in the SoC for any reason is a good one. All kidding aside, apart from a few dubious claims, I'm not aware anyone has ever found a round pearl while diving (blisters, sure).

Mantle pearls burst from the sac quite often. One they find their new resting spot, they tend to become fused to the the shell by new layers of nacre, hence a conjunction, which is double pearl, if you will. I enjoy studying these because they are excellent indicators of the pearl's age relative to the age of the shell.

Apart from blending with it's surroundings, any expelled pearl would become obscured by sediments within a few days, then become encrusted within weeks. Much like the shells from demised mollusks, the protein content of the pearl would be ingested by microbes over the seasons as the aragonite reverts to calcite. Pearls have survived ancient shipwrecks, but generally because they were preserved in an anaerobic situation, as opposed to cast upon the surface of the substrate. Even then, many of these pearls have lost lustre or become stained.

I really doubt attempting to salvage pearls from the substrate of pearl farms would be fruitful. If anything, ones found would likely be mere nuclei, under-mature or otherwise malformed and damaged.

Archaeology or forensic purposes perhaps, but certainly not to produce marketable gems.
 
...I'm not aware anyone has ever found a round pearl while diving (blisters, sure)...Mantle pearls burst from the sac quite often. One they find their new resting spot, they tend to become fused to the the shell by new layers of nacre, hence a conjunction, which is double pearl, if you will. I enjoy studying these because they are excellent indicators of the pearl's age relative to the age of the shell...

Hi Dave, I wouldn't generalize this to all nacre producing species. I found a few sale-able round pearls during inspection dive resting gently on the coral waiting to be picked! ;)
I even witness a beautiful round pearl rejected in front of my eyes, slipped though my fingers and went straight into the stomach of a sweetlips (Haemulidae) swimming by! (no joke!)

Skib2000, very cool question!
 
I wouldn't generalize this to all nacre producing species.

I suppose how the shells are positioned during growout makes a difference. Naturally, mollusks are quite adept at orienting themselves. Usually anterior upward. I notice a few farmers hang shells posterior upward while some lay them flat in trays.

Intestingly enough, most natural pearls never leave the sea. They live and die with the animal. Over the centuries, one might be inclined to think there'd be an accumulation in certain areas. It would be an interesting (albeit costly) experiment to examine the substrate of an area of high incidence to see how many pearls could actually be found.

I found a few sale-able round pearls during inspection dive resting gently on the coral waiting to be picked! ;)

When you dive around farms often, it's reasonable to assume you'll encounter something like this. How long do you think they were there?
 
Yes you are bound to see those if you dive often.
It is quite difficult to quantify the time since rejection unless the shell died, then like for forensic you may estimate the time of death in correlation with the amount of flesh left in the shell, or the texture of the muscle (you play Sherlock in short!). :p
I have found pearls right after rejection (greedy fish part in previous post) as well as rejected pearls estimated to less than a week (coral part), there the amount of sodium compounds was very low. We also found in the substrate a pearl with heavy carbonation, but beneath this layer (removable with the nail) the pearl was in perfect condition, I estimate the later to have spent at least 2 to 3 months underwater. Sadly some of the pearls found in old dead shells are not as lucky, boring sponges and algae did so much damage that what you get is no longer a pearl.
 
We have sometimes been able to find pearls on the bottom of the farm...but the poor pearls are just too pitiful! Here I have 3 "recovered" pearls from the bottom and one of them even had a barnacle living in it! Compared to our carefully harvested pearls these are truly "the rolling dead" or "zombi pearls"...quite adequate for this time of the year! Care to buy "Zombi Pearls" for your undead Halloween costume this year? :confused:
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