Rock cycle crayon model

Shave crayons to make different "minerals", then compress and melt them to form "sedimentary" and "igneous" rock.
Science content
Earth/Space: Rock cycle, Earth Materials, Natural resources (5)
Lessons activity is in
  • crayons of different colours
  • pencil sharpener
  • foil mini pie cases
  • greaseproof paper
  • hammer
  • hair dryer

Use a pencil sharpener to make crayon shavings of different colours into the pie cases.
This represents sand and mud made up of different "minerals".
Fold several colours into greaseproof paper and hammer it flat. The minerals are pressed together into one piece of "sedimentary rock".
Place the pieces of sedimentary rock into a pie case, then heat with a hair dryer. As they start to melt together they represent "metamorphic rock", then as they flow together completely they are "magma" inside the earth. As they cool to form a mixture of minerals they are "igneous" rock.


Needs reworking to more accurately represent what happens in the rock cycle.

Do with just one colour crayon:
Nice formation of different kinds of igneous rock (resolidify melted crayon fast and slowly).

Do all on a piece of foil.
Use pencil sharpener/knife as a scraper to add a layer of one colour, fold over foil to press, then add another colour, fold over to press and stand on it.
Layers formed but still flaky - sedimentary.
Metamorphic - somehow give it a little heat so it starts to blend.
Fold up the sides of the foil and put in a tray of just-boiled water for melting. Better than a flame, which makes the crayon give off fumes.

Grades taught
Gr 7