I've taken one micaeous clay class at the local university. I use the micaeous pots on top of the stove almost daily. These are cooking pots and they make the food taste sweet. It's a shame not to use them for cooking. I love the way they look but I love the way they cook even more. It's a blast to be able to make your own stovetop and oven safe cookware. I also have taken them full of food from the fridge straight to the stovetop.
We fired to cone 014, very low fire, and then smoked them in a pit fire with lots of pine bark. The pit firing creates fire clouds and is for beauty. After coiling starting on a puke and smoothing them, we water-scrape them when they're leather hard or dry. Never waterscrape the inside and outside on the same day because you'll lose the pot. To waterscrape, use water or better, use a thick slip and a rib. After that, let them get bone dry and sand them with several grades of sandpaper while wearing a mask. Blow them or use an air hose to blow them to find flaws. Fix the flaws by pecking at them with a pin tool and filling them with slip. Sand those spots again and fix them again if they still have holes. You can use a rough tile or brick to rotate the rim or bottom on to get an even rim or flat bottom if it needs adjusting. Sand afterward. Finally, make a polishing slip out of mica and clay (I don't have the recipe) and polish til your arms fall off. This gives a higher mica content to the outside and is for looks.
My teacher explained that mica burns out at higher temps. We could fire to cone06 with the locally dug clay or the commercial micaeous clay, but it might not be able to be used on the cooktop. The low fire cone 014 maintains the mica content and makes it stovetop worthy. New Mexico Clay sells a Mica Red clay which is what we use when we're not using locally dug clays.
Brian Grosnickle was my teacher. http://www.micaceouscookware.com/ Brian has videos on his website on his forum on the process.
His teacher was Felipe Ortega. He is an Apache medicine man in addition to a potter and teacher. Felipe did a lot to revive the 800 year old micaeous tradition in northern New Mexico. http://www.felipeortega.com/
I hope this helps. Sorry I can't answer questions about your locally dug clay.