A rainbow of mineral micrographs.

LINKS

Atlas of Rocks, Minerals, & Textures

UNC-CH
Geology Dept.

Rocks Aren't So Heavy, Online
by Cate House

Textbooks are expensive. They’re also a pain to lug around. By creating an electronic atlas of igneous and metamorphic rocks, Allen Glazner, professor of geology, has saved his students some money—and their backs, too.

Geology students spend a lot of their time studying rocks, looking at pictures and noting their properties. “But books with high-quality images are expensive and difficult to update in a timely manner,” Glazner says. “When you need to add an image, you have to create a whole new book.”

So Glazner decided to take his textbook online. With funding from an instructional technology grant, Glazner and graduate student Kent Ratajeski bought a scanner and began work.

A photomicrograph of a thin section of clinopyroxenite.

Ratajeski made photomicrographs of thin sections of the rocks—illuminated by polarized light—then scanned and organized the images on a web site. The result is a comprehensive online atlas of rocks, minerals, and their textures.

“It’s a great teaching tool,” Glazner says, “and it can be expanded easily.”

The images are shown under polarized light because this special type of light illuminates them, so that you can see the various properties. The different minerals found in a rock, for instance, show up as different colors. “Without the polarized light,” Ratajeski says, “many of the minerals would look alike.”

Apparently the web site has helped out more than just Glazner’s geology students. “The response has been incredible,” Ratajeski says. “We’ve gotten email from geologists all over the world, in places like Australia, Brazil, and Eastern Europe, who want to use our web site for their own classes and instructional purposes.”

Even if you’re not a geology student, it’s worth checking out the site for all of its cool images.

Glazner's web site was featured in the April 9, 1999 issue of the journal Science.

Article by Cate House
© Copyright 2000 Endeavors magazine, The University of North Carolina at Chapel Hill. All rights reserved.

What do you think of this story?
Let us know.