This is it. The largest volcanic Pumice sample we have ever seen... and it still floats! In fact, during the spring thaw in the mountains of Oregon, you can see these huge pieces of pumice floating down the rivers! A strange sight indeed. This stuff makes a great density demonstration -- one your students will remember for a long time. Totally cool!Use with our Ironwood Samples for a fun and thought provoking lesson; the rock that floats with the wood that sinks!