So I have a shelf in my workshop which has about 10-12 different types of minerals which I’ve sourced from Southwest England. There’s weathering feldspar, pieces of granite, quartz,
tin oxide mineral, galaena, china clay, copper oxide - malachite, calcite, flint, Devon yellow clay (processed, made into a pot and fired)!.
I make pots with porcelain and please myself with the conceit that all the materials could have been sourced locally for this clay. There is even a source of bentonite in Cornwall - I don’t have
a sample unfortunaely.