Sinonimi: pumice stone
ETYM Latin pumex, pumicis, prob. akin to spuma foam: cf. as. pumic-stân. Related to Pounce a powder, Spume.
A light glass formed on the surface of some lavas; used as an abrasive; SYN. pumice stone.
Light volcanic rock produced by the frothing action of expanding gases during the solidification of lava. It has the texture of a hard sponge and is used as an abrasive.