GAHHHHH!!! Get it off! Get it off!

What the hell IS this stuff? This is after repeated scrubbings with soap, then alcohol, then ammonia. It came off my new "inkstone" when I cleaned it.

My good friend Wang, he say this is inkstone, but it's clearly not what is traditionally called an inkstone -- a stone for grinding black ink sticks. There's a tiny well under the lid, and I'm guessing it was meant to hold the pasty red ink used for chops (signature stamps).

The orange may be a dye used on the stone to make it a more "desirable" color. Or it may be old chop ink, though it seems the wrong color. I'm hoping it's dye, because chop ink is made of cinnabar (mercury sulphide) and castor oil.

That's all I need: to go mad and shit myself.