[pieguana (OP)]

My Girl Scout troop of 8- and 9-year-olds is working on their "Potter" badge-- as in clay, not Harry. We've worked with polymer clay and will also work with mineral clay. I'm looking for a good, hands-on demonstration of the properties of clay-- perhaps something about plastic deformation. We made "slime" (aka "flubber"), from glue and borax already. My girls are very science-oriented and love these sorts of activities, so I'm hoping to bring some materials science to what is currently a very non-science project.

I welcome your suggestions!

Thanks, Jen

[CliffordK]

I've seen soil with grey clay that is almost pure enough to make stuff out of, although I've heard that impurities cause problems with firing objects.  Perhaps there would be a good place around your home town to dig some.

Here is a nice video about making one's own clay, along with some notes about plasticity of the clay, and what to select.

http://ceramicartsdaily.org/ceramic-supplies/pottery-clay/going-local-how-to-dig-and-process-your-own-clay/

As well as a description of making one's own clay.

http://www.goshen.edu/art/DeptPgs/rework.html