KBC 2024| Which of these is a volcanic stone, the pieces of which are rubbed on skin to make it softer? 

KBC 2024, The options of the question – Which of these is a volcanic stone, the pieces of which are rubbed on skin to make it softer?

A. Chalk

B. Lignite

C. Anthracite

D. Pumice

The answer is D. Pumice