Geology

Arizona isn't all desert. Take Grand Falls, aka "Chocolate Falls." It is dry most of the year, but when it rains, this waterfall pours.

By Patty Rasmussen

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

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

The element lithium is one of just three created during the Big Bang and has been used for mental health care for decades. But now it's in higher demand than ever before.

By Allison Troutner

Cinnabar's bright-red pigment has been used in jewelry, pottery and makeup for millennia. But cinnabar is also the primary ore for mercury, making it a dangerous mineral if the particles are inhaled.

By Allison Troutner

The rose-red mineral rhodonite was first discovered in the 1790s in the Ural Mountains of Russia. Today it's found globally and is associated with compassion, love and healing.

By Allison Troutner

Mountains might look like they're stoic and still, but research shows otherwise. Massive ones, like the Matterhorn, are moving all the time, gently swaying back and forth every few seconds.

By Richard J. Sima

Waterfalls are mainly reliant on precipitation to keep flowing. Here are six famous waterfalls that slowed to a trickle when drought set in.

By Laurie L. Dove

Nutty Putty Cave, near Salt Lake City, Utah, was discovered in 1960 and sealed up forever in 2009. This is the story.

By Dave Roos

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.

Not all diamonds are found on dry land. Many turn up in sediments below the ocean's surface. You just have to know where to look.

By Mark Mancini

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

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.

This ancient rock, which forms above copper deposits, is beloved for its swirling patterns and vibrant green color. It's dazzled humans for millennia as jewelry and even in décor.

By Carrie Whitney, Ph.D.

Tanzanite is so rare, it is sourced from just 8 square miles in Africa. It was first discovered in the late 1960s and it burst onto the jewelry scene thanks to Tiffany & Co.

By Carrie Whitney, Ph.D.

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

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.

It's found all over Earth — and Mars, too. It's the main source of iron but is also used in jewelry and painting. Get to know the amazing mineral hematite.

By Trevor English

Drones are helping researchers bolster scientific understanding of the ecology of a greening Arctic.

By Lesley Evans Ogden

One term might give you the impression of something grand and mysterious, while the other makes you think of claustrophobia-inducing environs that threaten human life. But what's the real difference?

By Nathan Chandler

Birds are — quite literally — living dinosaurs. Our quiz will test your knowledge of the fluffy, downy and winged dinos of the bygone Mesozoic era, from little Microraptor to the enormous Yutyrannus.

By Mark Mancini

The Pacific's Ring of Fire is a 25,000 mile long "ring" that's home to 75 percent of all the world's volcanic activity and 90 percent of the planet's earthquakes. So what makes this area so active?

By Mark Mancini

Not all fossils are found on dry land. In fact some of the most fascinating fossil finds in history have been submerged for centuries.

By Mark Mancini

"The 26th century" doesn't roll off the tongue as easily as "the 21st century" does. But that hasn't stopped us from imagining what our hometown planet will be like in a few hundred years. Any guesses?

By Robert Lamb

Mountain Lake in Virginia is best known for its starring role in 'Dirty Dancing.' But today, it's nothing more than a muddy pit that's all but dried up ... and geologists think they may know why.

By Stephanie Parker