Light, Rough Volcanic Rock Used to Exfoliate Feet
This page is the CodyCross answer for the clue below from Space Exploration, Group 904, Puzzle 4 (Intense Training).
Question is: Light, Rough Volcanic Rock Used to Exfoliate Feet
and the answer is: PUMICE
Word Meaning:
PUMICE — A light, porous type of pyroclastic igneous rock, formed during explosive volcanic eruptions when liquid lava is ejected into water or air as a froth containing masses of gas bubbles, which are frozen into the rock as the lava solidifies.
Definitions from Wiktionary.