Education and Careers

This activity is an introduction to the rock cycle using chocolate. Chocolate has the ability to be ground into small particles (weathered), heated, cooled and compressed just like rocks. Unlike rocks this can all be done safely and at reasonable temperatures, using the chocolate to create sedimentary, metamorphic and igneous chocolate and at the end of it all can make a tasty treat.

Materials

• Blocks of Dark and white chocolate
• Source of hot water 
• Aluminium foil and/or aluminium foil cake cups 
• Container to hold hot water 
• Simple scraping device e.g. plastic knife

To make Sedimentary Chocolate

• Scrape some small sized shavings from your chocolate blocks
• Gather these scrapings onto a piece of aluminium foil and press down on them. you could fold the aluminium foil and then press on the chocolate shavings (Children may want to stand on the foil packages) the coherent bunch of chocolate scrapings in the foil is now equivalent to sedimentary chocolate

To make Metamorphic Chocolate

• Place a small pile of your sedimentary chocolate and maybe some of your original shavings not used and maybe one or two small chunks from your original block into aluminium foil or a cake case
• Float this on hot water
• Watch as the heat from the water transfers to the foil and to the chocolate which should start to melt
• Remove the foil when the chocolate is soft to the touch (use the plastic knife or something to test this not fingers)
• Let the chocolate cool
• The partially melted and cooled chocolate is now the equivalent of metamorphic chocolate.

To make Igneous Chocolate

• Place a small pile of sedimentary and metamorphic chocolate and some chunks from original block into aluminium foil or cake cup.
• Float this on very hot water
• Watch as the heat transfers from the water to the foil and then the chocolate and it starts to melt
• The chocolate should be allowed to melt until a smooth liquid forms
• Carefully remove the molten chocolate and let it cool. Your totally melted and cooled chocolate is now equivalent to igneous chocolate