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  • In this activity, students make chocolate fudge using three slightly different combinations of ingredients to model the different proportions of minerals in basalt, andesite and rhyolite rocks.

    By the end of this activity, students should be able to:

    • describe the features that are similar between the three varieties of fudge and the three volcanic rocks
    • match which fudge ingredients correspond to which rock minerals
    • describe ways in which the fudge models do not match volcanic rocks well.

    Download the Word file (see link below) for:

    • introduction/background notes
    • instructions on what you need and what to do
    • ideas for extending your students
    • fudge recipes.

    Related content

    Before starting this activity, see the article Types of volcanic rock. It looks at the different types of magma associated with different volcanoes – when the volcanoes erupt, different types of rock are formed – basalt, andesite and rhyolite. Included is a video, in which Professor Richard Price describes the differences in rocks.

      Published 9 April 2010 Referencing Hub articles
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