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Joint Earth Science Education Initiative - Crystal Sizes


The process of igneous rock formation by the cooling of magma.  It can be used to illustrate how the rate at which molten rock cools affects the size of the crystals that form within the solid rock – rapid cooling producing small crystals, slower cooling producing larger ones.

Type of Activity

group work



Age Group

11 to 14 years

Hands-on practical activities or ideas for front of class demonstrations