Crushing on ice

This week I have (mostly) been doing the most laborious part of the process of making my geological pots - a series of quick 700C firings to calcine small rocks and then...

....banging away in my steel mortar and pestle to get them down to 2mm or less grit. Most have been OK but the limestone I collected from the Malvern Hills and a Cumbrian Rhyolite were INCREDIBLY hard. My arms and shoulders are still aching.

This image shows a finished crush of the oldest rock that I have collected so far - a PreCambrian partially metamorphosed granite that is around 800 million years old- ready for the ball mill.

I'm finally ready to mix up my glazes and start glazing pieces for the firing. It's going to be longer than usual (three days instead of two) so I am using my stiffest (most refractory) mixes to allow for the extra ash and heat work. I also did a test firing today with new Leicester materials and firing those Worcester Carboniferous clays to cone 10 to see if any of them can withstand it!