A tale set in stone

10 Rock Solid Facts About Geology To Rock Your World

Image: NEOM

Underneath a (mostly) humble appearance, rocks hold within them fascinating stories of our planet's origins. From the depths of the Earth to the surface, each rock has its own tale to tell. Luckily, you don’t need to become a geologist to learn a bit more about the origins of the rocks and minerals that make up our planet. Whether you are an aspiring rock hound or a science enthusiast, you will surely find these 10 intriguing facts about rocks and geology fascinating!

Image: Daria Volkova

The oldest rock of terrestrial origin was found in Western Australia and dates back a staggering 4.4 billion years. Known as the Jack Hills zircon, this ancient rock offers a glimpse into the Earth's infancy, having endured eons of geological turmoil virtually unchanged. However, it’s far from being the oldest rock found on Earth, as many meteorites can be much older. In fact, the oldest rocks found so far are Murchison meteorite particles, determined to be 7 billion years old —older than our planet, even older than the Sun!

Image: Oliver Paaske

Nothing is permanent on our planet, not even rocks! The rock cycle is a fundamental concept in geology, illustrating how rocks transform from one type to another over time through processes like weathering, erosion, deposition, and lithification. It's a dynamic process that shapes the Earth's surface, and it’s driven by some of its most fundamental forces, like plate tectonics, erosion, and the water cycle.

Image: Wes Warren

Rocks aren't just stone; they're time capsules. Fossils embedded within sedimentary rock layers provide invaluable clues about past life forms and environments, helping scientists reconstruct the Earth's ancient ecosystems. Fossils present themselves in many different forms and shapes, and examples include petrified bones, shells, imprints of animals or microbes, organisms preserved in amber, hair, and even DNA remnants.

Image: Caleb Jack

Wood can become a fossil too, given the right conditions —and a boatload of time! As different minerals replace the original materials present in wood, taking their shape, even an entire tree can be transformed into stone over millions of years. Petrified forests, like Arizona's Petrified Forest National Park, offer a glimpse into prehistoric landscapes, providing invaluable insights into ancient climates and ecosystems

Image: Nick Fewings

What looks like a rock sandwich —layer upon layer of different colored and textured rocks— you have likely gazed into Earth’s deep past without realizing it. A common sight on heavily eroded rock surfaces (like canyons), rock strata reveal the sequential deposition of sediment over time.

While common sense tells us that older layers are found deeper, while younger layers must be on top, this is not always the case, as many processes can alter the shape of the depositions. By studying these layers, geologists can unravel the Earth's history, identifying different periods of geological activity.

Image: Irina Iacob

Minerals should not be confused with rocks, although they are closely related. In fact, minerals are the building blocks of rocks. These peculiar structures form through various processes such as crystallization from magma, precipitation from solution, or metamorphism under high pressure and temperature. Each mineral has its own unique properties and characteristics. Common examples are quartz, halite (also known as rock salt), and diamonds.

Image: Jan Kopřiva

Ice, a substance seemingly ephemeral and transient, holds a surprising geological distinction —it is technically a mineral. According to the International Mineralogical Association, a mineral is defined as a naturally occurring inorganic solid with a definite chemical composition and an ordered atomic arrangement. Remarkably, ice meets all these criteria. Bet you won’t look at the ice on your drink the same after this!

Image: Pascal Debrunner

Mountains, Earth's sleeping giants, are actually more awake than we realize. Born from the collision of tectonic plates or from explosive and violent processes inside our planet, these massive landforms are created as the layers of rock are pushed upward, becoming towering peaks that shape landscapes and influence climates. Although most mountains take millions of years to form, in some cases volcanic mountains can seem to appear from nowhere over a few years!

Image: Jamie Hagan

The geological time scale divides Earth's history into distinct periods, epochs, and eras based on significant geological and biological events. Beginning around 4.5 billion years, with the formation of planet Earth, it extends up to current times, providing a comprehensive framework for understanding the evolution of our planet. Currently, we live in the Cenozoic Era, which covers the last 66 million years, and it is characterized by the dominance of mammals, birds, and flowering plants.

Image: Jeremy Gallman

Erosion is a natural process that wears away rock and soil, sculpting landscapes over millennia. Factors such as water, wind, ice, and gravity play a role in shaping the Earth's surface, from towering cliffs to winding canyons. While erosion is always a natural process, human activity can affect the rate at which it occurs. In the Appalachian Mountains, intensive farming practices have caused the rate of local erosion to speed up to 100 times the natural rate, disrupting ecosystems and creating all sorts of problems for the local population.

Superstitions that still make us knock on wood

Ten common superstitions and their surprising origins

We're rational adults living in the 21st century. We have smartphones, streaming services, and GPS navigation. Yet somehow, when a black cat crosses our path, we still feel that little twinge of "uh oh." Let's explore ten classic superstitions that continue to haunt (and amuse) us today.

Image: Savannah B.

Drop a mirror and watch it shatter? Congratulations, you've just signed yourself up for seven years of misfortune—or so the superstition claims. This belief dates back to ancient times when mirrors were rare, expensive, and thought to reflect your soul. Breaking one meant damaging your very essence, which would take seven years to "regenerate." That's quite the warranty period for your spiritual well-being.

Image: Jilbert Ebrahimi

See a ladder propped against a building? Better walk around it unless you want bad luck following you home. This superstition actually has some practical roots—walking under a ladder is genuinely dangerous since paint cans, tools, or clumsy workers could fall on your head. But the mystical explanation is even more interesting: a ladder against a wall forms a triangle, which represents the Holy Trinity, and walking through it was considered a sign of disrespect to the divine.

Image: Kristin O Karlsen

In medieval Europe, these sleek felines were associated with witches and dark magic, making them the least popular pet choice for the superstitious. Cross paths with one, and you were supposedly inviting misfortune into your life. Never mind that black cats are just regular cats with darker fur—superstition doesn’t care about logic.

Ironically, in some cultures, black cats are considered good luck, which must be very confusing for the cats themselves. Are they harbingers of doom or furry little fortune cookies? It all depends on which side of the ocean you're standing on.

Image: Ryoji Iwata

Popping open an umbrella inside the house is a big no-no in the superstition handbook. The origins of this belief are a bit murky, but one theory suggests it offended the sun god to use a shade-providing device indoors, where the sun doesn't shine anyway. Another explanation is more practical: early umbrellas had stiff springs and metal spokes that could genuinely hurt someone or knock over valuables when opened in tight spaces.

Image: K Adams

Say something good about yourself—"I haven't been sick all year"—and watch yourself immediately reach for the nearest wooden surface. The ritual supposedly prevents your boastful words from jinxing you and attracting bad luck's attention. Its origins trace back to ancient tree-worshipping cultures that believed spirits lived in wood and could offer protection if properly acknowledged.

The best part about this superstition is how flexible it is. Can't find real wood? Knock on your head (insert your own joke here). Some people tap twice, others three times—there's no official protocol, which is refreshing in the otherwise rigid world of superstitions.

Image: Nik

This superstition combines two separate fears: Friday was considered unlucky because it was the day of Jesus’s crucifixion, and the number 13 has been deemed unlucky for various reasons, including being one more than the "perfect" dozen. Put them together, and you’ve got a day so notorious it inspired an entire horror movie franchise.

The funny thing is, there’s no statistical evidence that more bad things happen on Friday the 13th than on any other day. Yet hotels often skip the 13th floor (jumping from 12 to 14), and some airlines avoid having a 13th row.

Image: ekaterina shishina

Knock over the salt shaker at dinner, and tradition demands that you immediately toss a pinch over your left shoulder. Why? Because the devil was supposedly lurking behind your left shoulder, waiting to cause mischief, and throwing salt in his eyes would temporarily blind him. Salt was once incredibly valuable—Roman soldiers were even paid in salt, giving us the word "salary"—so spilling it was genuinely wasteful and considered an invitation for bad luck.

Image: Roman Manshin

"Find a penny, pick it up, and all day long you'll have good luck"—but only if it's heads up. If it's tails up, some versions say you should flip it over for the next person or leave it alone entirely. This is one of the more optimistic superstitions, suggesting the universe occasionally scatters small fortunes in our path. Given that a penny is worth one cent, the universe isn't exactly being generous, but it's the thought that counts.

Image: Towfiqu barbhuiya

When someone sneezes, we automatically say "bless you" or "gesundheit" without really thinking about why. The tradition supposedly started because people believed your soul could escape through your nose during a sneeze, or that the sneeze temporarily stopped your heart, leaving you vulnerable to evil spirits. By blessing the person who sneezed, you were offering spiritual protection during this brief moment of weakness. It's surprisingly dramatic for such a common bodily function.

Image: Toni Reed

Ever notice how someone playing poker, bowling, or trying any new activity for the first time often experiences unexplainable success? That's beginner's luck, the superstition that newcomers are temporarily blessed with good fortune, perhaps because fate wants to encourage them to keep trying. It's a convenient explanation for why your friend, who's never bowled before, just rolled a strike while you, the experienced bowler, keep hitting the gutter.

Of course, there are practical explanations: beginners aren't overthinking their moves, aren't burdened by bad habits, and aren't feeling pressure to perform. But where's the fun in that? It's much more entertaining to blame supernatural forces for our defeats.