Pumice

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Pumice \Pum"ice\, n. [L. pumex, pumicis, prob. akin to spuma
     foam: cf. AS. pumic-st[=a]n. Cf. {Pounce} a powder, {Spume}.]
     (Min.)
     A very light porous volcanic scoria, usually of a gray color,
     the pores of which are capillary and parallel, giving it a
     fibrous structure. It is supposed to be produced by the


     disengagement of watery vapor without liquid or plastic lava.
     It is much used, esp. in the form of powder, for smoothing
     and polishing. Called also {pumice stone}.
     [1913 Webster]

From WordNet (r) 2.0 [wn]:

  pumice
       n : a light glass formed on the surface of some lavas; used as
           an abrasive [syn: {pumice stone}]