Texas Tech University

Geology Can Rock Your World

Glenys Young

September 16, 2015

Collect Rocks Day focuses on the hobby that is a lifelong passion for some.

Cal Barnes

Cal Barnes, a professor of geology in the Texas Tech University Department of Geosciences, says he's been interested in rocks for as long as he can remember.

“My first interest was throwing rocks into water, the usual kid stuff,” he laughed. “I started collecting, probably when I was 8 or 9 years old. At first you're interested in colors and patterns and things like that.”

Barnes grew up around the gravel farm roads of Eastern Nebraska, where gravel comes out of pits along the Platte River.

“The gravel there is very diverse, very interesting from a kid's standpoint: everything from fossils to petrified wood, agates and pieces of the Rocky Mountains that have come downstream,” he said. “As kids we would go down to the gravel pits on weekends and sift through the leftover material. We'd walk out with these big rocks. You couldn't do that these days because of safety issues, people would have a conniption. But I wound up with as many samples, as many rocks as my pockets would hold.”

Family vacations to Minnesota expanded Barnes' horizons, showing him gravels full of Lake Superior agate, which he wasn't familiar with. As he learned more about rocks, he expanded his skills, too, with a new interest in lapidary: amateur rock-cutting and polishing.

“As my mother would say, I have all these rocks; I should do something with them,” he laughed. “So I did that for a while. But ultimately you get interested in mineral specimens, so when I started seriously collecting I began collecting minerals.”

Still collecting rocks while he was in college, Barnes changed his major to geology after realizing his initial choice of electrical engineering was not what he wanted to do.

“I thought of geology as a hobby, which is reasonable,” he said, “but the switch came very easily so I've stuck with it ever since.”

Barnes holding rock

Some people don't understand what all can be gained from the study of rocks, Barnes said.

“There are the economic issues that are important for most people,” he explained. “Oil and gas come from rocks, so from an energy perspective, with the exception of renewable energies – wind and hydropower and so on – oil and gas and coal are all extracted from geologic materials. And so, our economy, our society is dependent on that.

“And then, although a lot of people don't think about it, everything we touch on a daily basis has a geologic origin. Concrete comes from sand, gravel and limestone. Your cell phone wouldn't work without the rare earth elements in it. We think about buildings made of wood, but the tree has to grow in something. Soil is a geologic material. Purely from an economic and societal standpoint, geology is extraordinarily important.”

That doesn't even factor in knowledge about our world that can be gained.

“Earth has a 4.5-billion-year history and one of the things geologists enjoy doing is trying to unravel that history, and in order to do that, we have to study the rocks because they're the only things that tell us anything about the history,” he said. “If we're interested in learning the age of a sample or we're interested in the pressures and temperatures under which the rock crystallized, those are all things that are actually embedded in the minerals that make up the rock. We're like historians – our goal is to take all of these different lines of information and then construct a geologic history and push that history as far back into the past as we can.”

After decades of studying rocks and minerals, Barnes said he still gathers anywhere from dozens to hundreds of rock samples each summer during field research. Because he deals with so many, he doesn't have one that he considers his favorite.

“I do have a number of samples I will show to people and try to make them jealous,” he laughed. “This piece is opal, and some of it is gem-quality. So when the appropriate person is in the room, I will hand them that and say ‘here's a little bit of gem opal' and with any luck they'll be jealous. I have a lot of specimens around, but mostly they're things I use for teaching or illustration or things like that. My job now is to get other people interested in rocks: they don't have to collect them, but it's nice for them to have an interest.”

From his roots throwing rocks into water, Barnes has progressed into the deepest questions of geology.

“For most professional geologists, we're not only interested in the history, we're interested in the way the history developed: the geologic process,” he said. “There's a lot of geologic information out there – some people would say trivia – that we all need to know as geologists. But at some point, that becomes less interesting than understanding the hows and whys of how things happen.”

For anyone interested in learning about rocks or minerals, Barnes said many resources are available in Lubbock.

“If someone is interested in looking at rocks or minerals as something that's pretty or decorative, then the best thing they could do is join a group,” he said. “For example, Lubbock has the Lubbock Gem and Mineral Society. Go to one of their meetings and see what people do in terms of collecting and lapidary – they have a show every year where people display the kinds of things they do. Many of them are very serious amateur geologists or amateur mineralogists or whatever. You can learn a lot from them.

“If you're interested in more of the geologic history and geologic process, once you get past watching Nova programs and so on, it's worth taking a class or two,” he added. “In Lubbock, of course, that's easily done. We teach a number of classes that non-major geologists can take.”

His best advice to new rock collectors is just to follow where their interests lead them.

“From a former collector's standpoint,” Barnes said, “if people find that sort of thing interesting, and as long as they follow the rules – don't trespass, don't collect in national parks and so on – it's a lot of fun and you're bound to learn something you didn't know.”