What is Rock Weathering?

Ah, the weather. Rain, wind, snow, ice, heat and cold all affect the nature and appearance of the Earth’s exposed rocks. Rocks and minerals that are out in the open over time will change the way they look due to the weather. The heat and cold will make the rocks expand and contract which can cause cracking and flaking.

Geology is all around you!

Whether you know a lot about geology or just a little, you probably know that the Earth’s crust and the material below it are made up of rocks and minerals. There are hundreds of varieties of rocks and minerals and each one has its own unique history from the time it was formed to the time someone finds a specimen and adds it to their collection

Ask-a-Geologist #19: What Gives Amethyst that Pretty Purple Color?

Lily wrote to us and asked about the mineral amethyst. Specifically, she wants to know what gives amethyst that beautiful purple color. In this video, we talk about why amethyst is purple, its relation to quartz and an interesting fact about how citrine fits into that mineral family.

Rock Layer Folding Experiment

lthough the land you stand on seems like it is firmly in place, it is actually moving. The Earth’s crust is divided up into pieces that are called “plates.” These plates are slowly moving around the Earth. While they are moving they sometimes bump into one another which cause the rocks on the plates to fold and push their way into mountains. All rock layers are originally created horizontally. This is a simple experiment that is great for showing the possible effects when pressure is applied to horizontal rock layers.

The Fizz Test for Limestone & Marble Rocks

Many rocks can look alike. Sometimes telling the difference between a limestone or marble and other rocks such as shale and quartzite can be difficult. One way geologists test the rocks is by performing the acid or “Fizz” test. Calcite is the main component of limestone rocks and its varieties like oolitic limestone, fossiliferous limestone, coquina and marble. The calcite mineral is made of calcium carbonate which reacts with acid. Other varieties of calcium carbonate minerals such as aragonite and dolomite will also fizz during this test.

Growing Salt Crystals is a Fun Geology Experiment for Kids (and adults, too)!

Hey Mini Me Geologists! Try this fun experiment to learn more about growing salt crystals. Did you know that the salt you put on your food is actually a mineral? Salt forms naturally by precipitation or evaporation. In this experiment, you will watch salt crystals form by precipitation because it is just more fun than watching water dry and leave salt behind, although you can try that method, too. Grab an adult to help you with the stove and boiling water but the rest you can do on your own. In nature, salt will precipitate from mineral-rich water in oceans or lakes so you will simulate ocean water to grow your crystals.

Ask-a-Geologist Q&A Video #17: Can I Be a Geologist?

This week I am answering a question that I received from two readers, Alliondra and Alexandria. Their questions were so similar that I thought I would answer them together. They want to know:

Can I be a geologist some day and how can I make my dreams of becoming a geologist easier? In this video, I’ll tell you a little secret about how I came to be a geology major in college along with some tips on things you can do to prepare for college and your career.

Ask-a-Geologist Q&A #16: What Types of Rocks Were Changed by High Temperature and High Pressure?

Cory wrote to us and asked: What rocks are changed by high pressure and high temperature? Metamorphic rocks are the rocks that change either physically or chemically by heat and pressure. The term metamorphic comes from the Greek words “meta” which means change and “morph” which means form. Metamorphism is a solid state change meaning that the minerals within the rock recrystallize in response to heat, pressure and the chemical reaction with hot fluids without melting the original rock.

Ask-a-Geologist #15: What Geology Field Notes Do I Take When I Find Rocks and Minerals?

Ellie wrote to us and asked what notes she should take when she finds rocks and minerals. Geologists use fancy notebooks with waterproof paper but a simple notebook and pen will work just fine. Watch this video to find out what notes to take and how to organize your notebook for your collection.

Ask-a-Geologist #14: What are the Properties of Calcite?

Sophia asked: what are the properties of calcite? I’m especially interested in its cleavage directions and fracture pattern.