New and Improved Rock Cycle

After doing the crayon rock cycle with limited success I had to try a new way of doing things. In a quirk of timing just after  teaching it to my Year 10's I had the opportunity to do it as a demonstration lesson on a interview. This time I tried with playdough of different colours and textures. The playdough is less solid and rock like, but it has the advantage of sticking together when the rocks are sedimentary,and it is easy to break pieces off for weathering. The metamorphic rocks are less pronounced, but by working the playdough until all colours merge a satisfactory igneous rock develops. I think I shall work with the playdough version in the future.