My last year in college I needed one more credit in science. I decided to take Geology. If only I had taken that course early in my college career, I would have very likely chosen a different career path. That was one of the best classes I ever took! I loved it! So it’s no surprise when I tell you that teaching my hobby in the classroom creates all kinds of excitement in me.
Every year when I start off my rocks and minerals unit with all kinds of excitement like a child in a candy store, my kiddos look at me like, “It’s just rocks. Chill.”
Just rocks? I don’t know about that.
One of my favorite activities for teaching rocks, you may have seen around the web. I have been teaching it this way long before I ever saw it online (and it’s in my rocks and minerals unit). It all involves a little color.
I first gather an iron, a pencil sharpener, a few crayons, wax paper, and scissors. After I use the pencil sharpener to create some wax shavings in a pile, I get ready to demonstrate to my class the differences between the three rocks.
Igneous rocks are formed deep within the Earth and are formed by heat. I move my iron just a little close to the crayon shavings. They slowly start to melt. We discuss how they form crystals that are either long, course grains or short, fine grains based on the length of time it takes.
We then discuss sedimentary rocks. I cut a small piece of the wax paper and place it over the top of my second pile of crayon shavings. I add my science book to the top and apply lots of pressure. I act pretty dramatic and pretend to place a ton of weight on it. I then show students the results and together we discuss just how it would look after years, and years of even more pressure.
Finally, I get to metamorphic rock. Now technically, I suppose I could have placed the first two rocks created on top of one another to create metamorphic rock, but I just take my third pile and place a piece of wax paper over it. Then I apply the iron down on the wax paper – applying both pressure and heat. Just a quick 10 seconds or so does the trick. The kids love how it oozes everywhere.
To conclude my lesson, I provide each student with two different colored starbursts. I ask students to demonstrate to me how they would make each of three rocks. The results are always colorful and yummy!