</noinclude> [[Image:Pumice on 20 dollars thumb.jpg|right|thumb|200px|Pumice is very light]] :Cinder so bubbly that it floats in water. :http://en.wikipedia.org/wiki/Pumice :Pumice is a highly vesicular pyroclastic extrusive igneous rock of intermediate to siliceous magmas including rhyolite, trachyte and phonolite. Pumice is usually light in colour ranging from white, yellowish, gray, gray brown, and a dull red. Most of the time, it is white. As an extrusive rock it was made from a volcanic eruption. Pumice has an average porosity of 90%. Pumice is formed as pyroclastic material is ejected into the air as a froth containing masses of gas bubbles or vessicles, the lava solidifies quickly and the vessicles are contained in the rock. <br style="clear:both">
