facebook
twitter
rss
account
search
search
 

Scientists say pearls 'ratchet' themselves to form perfect spheres

June 19, 2013 at 2:32 PM   |   Comments

GRANADA, Spain, June 19 (UPI) -- Spanish researchers say pearls are the most perfectly spherical large objects in nature because they turn inside oyster tissue in response to movement.

Researchers at the University of Granada note flawless and highly prized pearls have perhaps the most perfectly spherical shape among all the objects in nature that are visible without a microscope.

Writing in a journal of the American Chemical society, they say the spherical shape results from a developing pearl's saw-toothed, or ratchet-like, surface, a texture that creates forces that cause the pearl to turn inside the oyster's tissues in response to movements in the environment.

The ongoing movement results in a spherical build-up of nacre (mother of pearl) deposited around a grain of sand or other foreign object in shellfish.

The rotating pearls may be unique example of a natural ratchet, the scientists said.

© 2013 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
Recommended UPI Stories
Featured UPI Collection
trending
Celebrity Couples of 2014 [PHOTOS]

Celebrity Couples of 2014 [PHOTOS]

Most Popular
1
Video shows scientists dissecting colossal squid Video shows scientists dissecting colossal squid
2
Attic window offers glimpse of life inside a wasp nest Attic window offers glimpse of life inside a wasp nest
3
Boeing may build NASA's space taxi Boeing may build NASA's space taxi
4
First 3D-printed car unveiled in Chicago First 3D-printed car unveiled in Chicago
5
The NSA will now map out the entire Internet The NSA will now map out the entire Internet
Trending News
Video
x
Feedback