'Soot' in the Bible

Then the Lord said to Moses and Aaron, "Take handfuls of soot from a furnace, and have Moses throw it into the air while Pharaoh is watching.

So they took soot from a furnace and stood before Pharaoh, Moses threw it into the air, and it caused festering boils to break out on both people and animals.

(Khet) Now their appearance is darker than soot; they are not recognized in the streets. Their skin has shriveled on their bones; it is dried up, like tree bark.