Plasticity Lab

In science class we recently did a lab on plasticity and how it relates to the earth's mantle. First, we gathered our materials: cornstarch, water, two small beakers, a spoon, a tray, an eyedropper, and food coloring. After that we put cornstarch in one beaker and water in the other. Then we put the water, and food coloring into the beaker with cornstarch in it and stirred it until it made an unusual substance. When I rolled the substance between my palms it became a solid ball, sort of like play dough. However, the moment I stopped applying this heat and pressure to the substance it melted in to a liquidy gel-like material. I would describe this mixture as both a solid and a liquid. I have never seen anything like it before. When I put my finger in slowly it sunk into the mixture but when I put it in fast it did not. The reason that this relates to the earth's mantle is because the plasticity demonstrated by this lab is also the plasticity that is present in the upper part of the earth's mantle. All in all, this was a very fun and interesting lab.