Making the Rock Cycle STE(A)My

Image result for rock cycle

Other than the lactose intolerant, who doesn’t love chocolate? One thing that’s for sure is that kids do. Teaching the rock cycle is so often a dry, boring unit but with chocolate it can be made much more interesting, impactful, and can allow students to better understand the processes at hand! Using this STE(A)M (Science, Technology, Engineering, Art, Mathematics) activity can foster critical thinking, creativity, and intellectual growth in your students all under the guise of students getting free chocolate.

Materials you’ll need:

  1. Chocolate
    1. Varying colors and types work best – not all rocks are the same, right?
    2. M&Ms work well for this!
  2. Aluminum foil
  3. Some heat source like Bunsen burners or hot plates
    1. What you use and how it’s used can and should depend on the grade level.
  4. Water
  5. Toothpicks

Image result for m&m


In front of the class, place a piece of chocolate in an aluminum foil vessel and melt the chocolate. Once it cools and hardens, show the students how it looks – and then eat it!

Let them know that just like chocolate, rocks melt and re-harden all the time.


  • For students to get a better foundation for the activity they’ll be doing, set up some station activities they can do to show how sedimentary, igneous, and metamorphic rocks form. They can shave some chocolate for sediment grains, then compact them together and try to form one solid block.
  • They should partially melt that block of chocolate they just made with some chunks of other chocolate to see how metamorphic rocks form. They’ll put the foil over some hot water and once it slightly melts, use a toothpick to move it around! The different forms of chocolate should still be distinct.
  • For igneous rocks, they can use the metamorphic rock they just made, with or without some additional chocolate, and COMPLETELY melt it and re-cool it. This is how igneous rocks form!

(this can also be done with crayons – but don’t let them eat their rocks if you use crayons!)

Image result for crayon rock cycle


Let students form groups where they create a poster talking about how each of the three rock types can form from the others. This allows them to learn from each other, and allows you as the instructor to see what gaps they have in their knowledge.


This is where the students get to be more in charge of their rock cycle (and get to eat candy at the end). Challenge groups of students to create a rock of each type, with the most visible colors in it. For the sedimentary and metamorphic stages, this requires them to account for things like grain size, melting time and temperature, and how many colors they want to use. The group will present their rocks to the class and describe their process and at the end they all can eat it their own!

This is also another activity students could do at home that works similarly to this, but only for sedimentary rocks:


An exit slip posing a question that probes students to describe their process and how it modeled what geologists do to name/determine rock types would be a great elaborate!

Activity modeled from:


  1. Kate,

    I’ve been thinking about your question for a few minutes now, and I’m coming to the conclusion that anything solid at room temperature that melts at a relatively low temperature would probably work. That image was of crayons, and that’s something that works super well since it’s easy to get a lot of colors – but it doesn’t really resolidify all that well and is really brittle and flaky without too much force put on it. I thought of using candles and their wax but that could be too slow of a process? This also might sound weird but even butter might work? That’s such a good question that is so tough to answer!

  2. Katie,

    Omg looking back I totally agree with you about the Engage part being lackluster. I was struggling a bit to think of something a bit more exciting or enticing to start off with that still had to do with the same theme. I thought maybe of extreme modifications to a “chocolate rock” but couldn’t think of anything that would be plausible in a normal classroom. For instance, it could have been cool (no pun intended) to add water and freeze the “beforehand” and shatter it or something to show – albeit exaggerated – freeze/thaw erosion. I also thought of making some sort of volcano that spews out molten chocolate that could resolidify in interesting patterns like igneous rocks do. Those things are just hard to do for everyone and require a lot of forethought and preparation!

  3. Chris,
    I loved your blog post and relating a chocolate treat with the rock cycle. It’s super fun and super sweet and super poignant to it being Halloween season. For your exit slip are you gauging more of how they made their model or the actual process involved? I’ve never heard of this activity before though, it’s very cool. Could their be a way to incorporate a challenge with it? I love a good competition!
    Great job!

  4. Chris- I would love to be in this class making rocks out of chocolate. This sounds so fun, and what kid doesn’t want to mess around with chocolate? I appreciate how accurate this actually looks when finished. I feel some representations that are supposed to be “fun” can lead to misconceptions, but these melted chocolate pieces are visually representative of the different types of rock formation! I think the rock cycle is difficult to visualize for students because of the glacial pace of it. With natural occurrences that are this gradual, students need a sped up version to understand the process; and this does it right in front of them. Now, I don’t know a lot about rocks, but I am curious, do you think there are any other everyday items that may be able to recreate this process even more accurately? What else would you use within your classroom?

  5. Chris, nice blog post! I really enjoyed reading through it. I think using chocolate (especially if the students know that they can eat it at the end) is a great way to get their attention and interest in the activity!
    Is there any way you could extend the “engage”? I feel like it would be a very short demo and if these were high school students watching, they might be a little underwhelmed? I really like the concept, but maybe adding in different types of chocolate and using heat, then something like a heavy book to smash some of the chocolate to demonstrate the effect pressure can have would maybe add another element to the demo!
    I really like your elaborate section! Allowing students to be more in charge and collaborate with their peers make this a really good engaging activity!
    Again, great blog!

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