I know how dumb this sounds.

Hiking near some hot springs. Sister brought back (and left at my house) mud from the hot springs (great for skin). It's completely dried out now. Am I likely to have a problem taking it through the checkpoint?

It's big chunks. I'm just concerned that an ETD might hiccup if the mud has any kind of sulfur in it (the hot springs smell like sulfur).

I'm actually checking a bag this trip, but I'm afraid if I check the mud, it will look odd on the x-ray and trigger a bag search and I never like light fingers rifling through my stuff.

I guess I could check it in a second bag by itself.