Why do igneous rocks have different crystal sizes?

This activity simulates crystallisation from a melt at different rates of cooling of Salol (phenyl salicylate). It can be included in lessons on the rock cycle to model the cooling and crystallisation of magma to form igneous rocks. We have just added some video clips which show crystallisation on room temperature, cold and warm microscope slides.
These video clips are published with permission from the Earth Science Education Unit which provides no fee Earth science/Geology CPD to teachers and teacher trainees across England, Scotland and Wales, through workshops for schools, teacher meetings and teacher education institutions/organisations.





Click HERE to watch the video clips