My materials from the thrown-off trailings of the Alps, the alumina and silica built up and broken down over the years and their millions.
From quarries or road cuttings or overturned stumps revealing: here, this, use it. Use it how?: it has no instruction manual, so: test. Use it as I let it use it, some are nice and some are not and all are given—a wine has “terroir”.
They exist but to be found: start with historical documents, scientific publications, geological surveys; they’ll suggest what does or did exist. Geological coordinates and then Google Maps are any of them visible from the road or above: do any of them (still)(or “really”) exist? In the car then drive to the dot on the map and if it’s accessible dig down or dig out of a wall get the clay put it in a bucket. Put the bucket back in the car the car back to the studio the clay then process it, refine it (that is: let it dry completely, get it wet completely, put it through a sieve, let it dry again to a workable consistency (if it has a workable consistency), put it in the kiln and fire it to a succession of temperatures.
To answer the questions: (at what point) does it melt? does it turn vitreous? (how much) does it shrink or crack? what color is it?
When the answers known then: use the clay.
Some useable as throwing bodies, some for building, some as glazes to put on the formed pot. Some are stones or materials to be mixed with other materials to make glazes.
The clay is thrown or formed and then an object exists. I could finish it in my electric kiln more often I take it to another’s wood-fired kiln.
Two suitcases, then train–bus–car–foot, the kiln: firing the kiln, two days to chop wood & two days to stack the pots in the kiln & four-ish days to fire the kiln & four+ days to let it cool & one day to open.
The wood burns and flies through the kiln and with it, or what it is: melted ashes, they land on or in the pot and built up and give the pot a face a story from the specific kiln, its place in the kiln, the specific wood used and for how long in the firing. Firing with wood does not alone make a good pot, but it helps birth the pots I like.
Back home to assess. Reckon a 25% failure rate, structural or aesthetic. Some pots you hate on day 1 and then like, or some you like and then like, or some you like and then don’t.
A pot is done a new pot comes.