Volcanic Rock Used in the Bathroom for Smooth Skin
Puzzle 4 of Benefits of Pets Pack
Question is: Volcanic Rock Used in the Bathroom for Smooth Skin
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.