Excellent post Intuit and thank you for sharing.
Have you tried talking to the producershttp://www.vickihardin.com/links/ceramicsuppliers.html
about the possibility of milling and source variations to provide novel clay 'recipes' for potters? These would be different (and substantially cheaper to produce, btw) product grades.
I haven't contacted producers directly as the volumes I use of say a courser grade feldspar tend to be fairly minimal, around 200 pounds per year, and I didn't think to ask them if they'd want to deal with a quantity that small. Worth a shot though.....
However, you would think there would be specialty clay companies that offer unique clay body recipes. Or you could mine and beneficiate (stepwise mineral processing) your own clays. That would, of course, substantially increase your base materials costs.
My lament concerning Wonder Bread clays is due to the fact that while all the various regional ceramic supply houses produce their "own" blends, the base materials that they start out with tend to be pretty much from the same sources/mines hence the uniformity. Consequently I frequently end up doing what you suggest, and that is to source materials locally, excavation sites/mining cast offs etc and blend them to a base clay body. In the end that results in fewer pots however, hopefully they are more personal but which I have to charge a little more for with the hopes that the buyer can see/touch/feel/ "get" the difference...... developing an "eye" as I mentioned a few posts back. As an aside, if one can begin to "work locally", just as "eating locally" is now back in vogue, it does help to reduce ones carbon footprint as clays aren't being trucked from one side of the country to the other. Hopefully it will help to offset all the energy we potters burn up......
The vast majority of artists, potters in particular, barely scrape by financially - so they are left to be creative in their pottery arts using standardized materials.
Agreed, financially the road of a potter is not easy, however there are sucessful potters who do work right from the box. My students tend to be surprised when I bring in a bag of my clay for demos as it's much shorter and courser that what they're used to hence probably the demand for such a body might be fairly low from a producer stand point. They look for clays which throw and trim easily and fire out predictably while my concerns are somewhat different.
Regarding your failed Yakima trip: when you try to locate rock minerals that emerge at or near ground surface, check the state US Geological Survey technical reports (many available online, free); these documents may provide more exact locations for outcroppings with general coordinates. The USGS or local soil survey (NRCS) office for quad maps for vehicle access and check with the county on property ownership (unless you like to risks with onery owners).
Thanks for the tip regarding reports and the USGS office in Tacoma. I use a book titled "Roadside Geology of Washington" which is fairly good as well as being fairly precise. Accompanying me on my search was my 5 year old daughter, and while her enthusiasm for the search was as high or higher than mine, unfortunately her patience wasn't.
Then again, the trip was similar to much of ceramics, (my search for nezumi shino only to "find" kurojino) searching for something fairly specific, pink feldspar near Yakima, but coming away with something different, pinkish/marroon rock from White Pass. This too relates to some students who tend to want you to get them to the end point of the journey as soon as possible (product) rather than walk their own path (process) to reach their destination thus missing the joy of discovery as well as all the wonderful side trips.
Thank you for putting up with my ramblings and many thanks Intuit!