Foraged in Arizona.  A variety of blackClay, that didnt undergo much oxidation - Dusty,  irregular hardness, crumbly, flakey,  layered composition, No grit, Turns textured slush. Doesn’t stick.
- Starts with deep cementy metalic earthy tones, then mix of dirt and Basmenty richness, its Unique varity of earthiness thats words cant explain. Like Mineral Shale and dirt put together. 
Similar Items  - Black Shale, Montana Coal, Black oracea, black Ural .