JOHN R. FOSTER / SCIENCE PHOTO LIBRARY JOHN R. FOSTER / SCIENCE PHOTO LIBRARY
Egg sized pieces of pumice blown out of Washington State's Mt. St. Helens volcano during the May 18th, 1980 eruption. These specimens were gathered from the blast zone prior to the formation of the national monument. Full of bubbles that once held explosive gases, pumice has such low density that it easily floats on water.
Model release not required. Property release not required.