Clay – Incredibly Useful
Clay is found all over the earth, and throughout time it’s been incredibly useful to people. I’m Jim Metzner and this is the Pulse of the Planet.
Schroeder: When you push on something, it either is rigid or plastic. Clay has that property of being plastic when wet and being rigid when hardened or dried.
Paul Schroeder is a professor of geology at the University of Georgia.
Schroeder: It’s those exact properties of the clays that make them amenable to forming themselves into pots and clays and other things that people have used throughout time. People have also used clays for medical purposes.
We classify clays based on their structure and sometimes we refer to them as sheet silicates. The structure of the clay is very sheet-like, most like sheets of paper in a magazine. Generally it’s the clays that accommodate water and other materials, in between the sheets, that can make the clays swell and shrink.
Some clays can are almost like accordions. They can expand and contract, depending upon the conditions around them. So it’s a pretty amazing material.
The largest use in ancient times of clay was for pottery and then porcelain. Today the most wide use of clays, depending upon on what type of clay – is for paper coating, and ceramics and sanitary ware. But it’s also used as a filler that goes into plastics and tires, and also used in pharmaceuticals as a carrier for drug delivery. It’s used to apply pesticides and herbicides. Pretty much if you look anywhere around your room, there’s probably a clay in it.
Pulse of the Planet is made possible in part by the Center for Earth and Environmental Nanotechnology and the National Science Foundation. I’m Jim Metzner.