[Caitlin]

from google:

Trigem Designs: Cortez Pearls ... After they are removed from the shell, Cortez Pearls are washed in water, soaked in mineral oil for six hours, and then dried. ...
www.trigemdesigns.com/gems/cortez-pearls.php - 26k - Cached - Similar pages


Why?

[jshepherd]

They would be soaked in mineral oil which would penetrate the nacre increasing the shine, and adding moisture to the nacre. I would like to point out that I do not know a lot about the Cortez pearls, so I am not saying this is what they do, this would just be a reason for the mineral oil treatment.

Their is an old tale that says if you pass a pearl through a chicken it will expell lusterous and perfect. While I would not feed pearls to a chicken, this story is simply explaining that oils are good for the pearls.

[Caitlin]

Thanks. Interesting. This is what their site says they do. Would mineral oil be the best oil for this purpose?

[jshepherd]

I imagine it would, but I am really not sure. It is not a typical pearl treatment. I may try it with a few pearls just to see what happens...

I have a farm with actual chickens - I'm awfully tempted!!!

[Caitlin]

I woke up this AM thinking about a pearl "passing through" a chicken. I do not think that is too likely. I have raised chickens since childhood and never seen (or stepped on) a chicken poo with anything in it but goop.

A pearl is more likely to get stuck in the chicken's "crop"- a pouch on top of their wishbones, where they store the little rocks and pieces of oyster shell (calcium carbonate!) used to grind up their grains etc. as they do not have teeth. Stones and shells in this pouch do not pass on, only the ground up food does- by some mysterious process!

I would imagine that if a pearl got eaten by a chicken, it would rotate around in the crop until the chicken was harvested. It may very well get polished and rounded by the other stones and bits of oyster shell in this process.

Where would the oil come from?

Hmmm, I think the story of the chicken is just a wife's tale and nothing more. Not unlike the grain of sand theory circulating the world presently. I imagine the pearl would actually be destroyed in the chicken...

[purepearls]

I would equate it to wiping nice would furniture with oil. It is done to increase the luster and moisture in the pearls and it keeps the pearls from drying out.