[What does this clay need?]

Tried the coil around the finger test; absolutely no cracking. It’s very plastic. 
Another characteristic I forgot to mention is that it seems to dry extremely slowly. Much slower than the array of porcelains and stoneware clays I work with. 

[What does this clay need?]

New to this all, and thank you so much for these thoughtful responses. I will continue since the idea of the wild really intrigues me. Your comments will lead me on. Unfortunately, no kiln of my own yet but I will experiment in the ways that I can. 

[What does this clay need?]

10 hours ago, Kelly in AK said:

Beware. It’s a wild world you’re stepping into.  Maybe the clay has a high percentage of non plastic material, even though it’s throwable and feels plastic. If it’s actually sticky, then you ought to be able to “stick” a handle to it. Check out Tony Hansen on “splitting:”

https://www.digitalfire.com/glossary/splitting/

Sedimentary clays are often found in “lenses,” or lens shaped layers with sand, silt, and and silty or sandy clay. You might go back to your spot and see if there’s a more pure clay layer. Silty sandy clay can seem plastic when wet enough, yet the clay an inch below or above what you dug may be the sweet stuff. One way to differentiate that is by trying to break or crumble a totally dry piece in your fingers. The more difficult it is, the less non plastic material it has.

Sieving out the non plastics gets... complicated. The finer they are, the trickier it gets. I’ve found it much easier to collect clay that’s mostly clay.  

Another thought is to add a more plastic ingredient, like bentonite, Veegum, or ball clay. That will increase drying shrinkage, and the effort it takes to dry pots without cracks. 

14% shrinkage at bisque, cone 06-04, seems like a lot, and if it hasn’t melted by cone 6 (sounds like it’s on the cusp though) that's a wide firing range. 

Tony Hansen has done so much work on prospecting, testing, and evaluating wild clays, posting it free of charge on Digitalfire. The guy deserves a medal. It’s worth diving into what he’s written if you stay on this path.

I would say, what your clay needs is for you to test it more. Not melting by cone 6 means it’s different than 90% of clay on earth. Getting that sheen at cone 6, it’s what your teacher said, vitrification, maturation. There are just a lot of possibilities. Do some absorption testing. Too cool!!!

 

[What does this clay need?]

I have a dark (iron filled, I’ve been told) natural clay I dug from a foundation job nearby. Our neighborhood has a spring fed underground stream system running through it. 
I’m able to throw using it but it has some noticeable properties: while plastic, it has a tendency to sheer off if not super well-wetted, it has detectable fine sand in it but is quite sticky, it also does not adhere to itself. I attempted to put a handle on a mug I’d thrown, but there was no affinity when I tried to get it to attach. 

I’ve done a test bisque. The deep coffee-bean colored clay bisques to a brilliant brick red. About 14% shrinkage and it held its shape well.

When I ran it through a cone six firing it returned to its deep brown color and acquired a pretty sheen that my studio teacher said was probably the beginnings of vitrification. He suggested I try it at cone two. 

Does any of this information give anyone an idea of how I might make the clay a bit more workable?