Geology

To honor their prehistoric pasts, most U.S. states have designated official state fossils, ranging from trilobites to dinosaurs. Take our quiz to learn more!

By Mark Mancini

Decades after the massive conflict, reminders of battles linger in pristine Pacific waters.

By Christopher Hassiotis

Decades of fossil discoveries have revealed much about the extinct members of our hominid family tree, but we're far from having all the answers. What have we learned from some of these fascinating finds?

By Jane McGrath

The world of our far-future descendants may be as unrecognizable to us as our bustling, urbanized world would be to our bewildered ancient forefathers. Will energy drive many of those changes?

By Robert Lamb

The Doll's Theater of Carlsbad Caverns looks otherworldly and took ages to form. What other incredible sights await us below ground?

By Julia Layton

Diamonds are some of the most brilliant and expensive natural features Earth has to offer. This collection of images displays diamonds in all their uncut and polished shapes and sizes. Obligatory pictures of very large diamonds are included of course.

By HowStuffWorks.com Contributors

One grows from the ground and one from the ceiling, but sometime's it's hard to remember which is the stalactite and which is the stalagmite. How do they get there, anyway?

By John Fuller

Diamonds are beautiful and popular - but not everyone can afford these gems. While man-made versions are less expensive, most lack the luster and brilliance of the real thing, except moissanite. See how it compares!

By Melissa Russell-Ausley

The sea scorpion may have been the largest bug to ever live on the Earth, according to a recent find. Learn more about the giant sea scorpion.

By Josh Clark

Are dinosaurs real? Most people don't have to travel too far to answer that question in the affirmative with some kind of exhibit displaying dinosaur fossils. Or simply look at any bird you can see outside your home.

By Tracy V. Wilson

The 1993 movie "Jurassic Park" did a good job of bringing the idea of cloning dinosaurs into popular culture. It portrayed dinosaur cloning in a way that made sense to a lot of people, but is it really possible?

By Tracy V. Wilson

Every time a new fossil is found, one of the first things scientists determine is how old that fossil really is. But how do they determine it, and how can they be completely accurate?

By Tracy V. Wilson

Saber-tooth cats have long been likened to tigers, but they aren't tigers at all. While they share some physical traits and hunting practices with tigers, saber-tooth cats are also quite different.

By Tracy V. Wilson

Earthquakes and volcanoes get all the press. But the landslides they trigger are often more devastating. What makes the ground suddenly rip downhill, taking trees and homes with it?

By Jennifer Horton & Mark Mancini

From the Hope diamond to the shiny bits in instant coffee, crystals have always held the power to fascinate us humans. Are they more than just a bunch of pretty facets?

By Nicholas Gerbis

You likely heard that paleontologists uncovered a cache of dinosaur embryos, bone fragments and eggshells in China. You also may recall that we've made crazy leaps forward in genetics and genomics. Can we put the two together and create a dinosaur?

By Nicholas Gerbis

Trovants, found only in a small town in Romania, are stones that actually seem to move and grow. But are they alive?

By Jennifer Walker-Journey

There are caves all over the world, but some are in places that are hard to explore — hidden by rocks, ruins or even under ice. We've found seven secret caves you probably never knew existed.

By Stephanie Parker

Split as if by a laser, the Al Naslaa rock in Saudi Arabia's Tayma Oasis baffles scientists and amateur geologists alike. How did this perfect split happen?

By Laurie L. Dove

Curious about healing crystals and their meanings? Here's the lowdown on 12 of the most popular stones for wellbeing.

By Dominique Michelle Astorino

This ancient rock adorns King Tut's coffin and the Sistine Chapel. And at one time it was more precious than gold. What is it about this deep blue rock that has drawn us in for centuries?

By Carrie Whitney, Ph.D. & Austin Henderson

Tanzanite is so rare, it is sourced from just an 8-square-mile (20-square-kilometer) area in Tanzania. It was first discovered in the late 1960s and it burst onto the jewelry scene thanks to Tiffany & Co.

By Carrie Whitney, Ph.D. & Austin Henderson

The Mohs hardness scale is used by geologists and gemologists as a way to help identify minerals using a hardness test. How does it work?

By Carrie Whitney, Ph.D.

Not all deserts have sand and they're certainly not all hot. They're just extremely dry and have little vegetation. That means deserts are located all over the planet, including at super-high elevations.

By Sharise Cunningham

This beautiful pink quartz is found in numerous places throughout the world and is thought to be associated with unconditional love.

By Carrie Whitney, Ph.D.