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Revision as of 16:36, 8 October 2003 by Sandman~enwiki (talk | contribs) (revert vandalism)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)File:Different rocks at Panum Crater-300px.jpg
Top stone is obsidian, below that is pumice
and in lower right hand color is rhyolite (light color)
Pumice is a porous type of igneous rock. It is considered a glass because it has no crystal structure. Pumice varies in density according to the thickness of the solid material between the pores; some samples float in water. It is widely used as an abrasive for cosmetic purposes.