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The Sand Beneath Your Toes

Updated: Oct 22

Sand on the beach may look like a uniform sprinkling of tiny identical grains, but there is actually a remarkable variety of weird and wonderful components if you look closely...


Components of a grain of sand under a microscope

Next time you feel beach sand between your toes, remember this picture. This is what one sample of ocean sand looks like under a microscope.


Coral debris and tiny seashells make up some of what at first glance appears to be a nondescript mass of brownish specks. But bits of sea animals aren’t the only constituents: A piece of microplastic appears just below and to the right of center.

The bulk of sand isn’t marine organisms and (happily) microplastics. Most sand grains come from rocks on land, pounded by rain, wind and waves.


The color and texture of any beach’s sand reflect the local rocks and fauna. Quartz, tinted by iron oxide, and feldspar give many beaches with their light brown hue. Black beaches in Hawaii and Bali contain lots of obsidian, oozed out of volcanoes. And the gorgeous pink beaches in Bermuda and the Bahamas are courtesy of the shells of red foraminifera, single-celled organisms that call the surrounding waters home.


The image comes courtesy of @macrofying, a macro photographer who posts on Instagram and Twitter.

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