March 25, 2013 | Geology.com
Pumice is a light-colored, extremely porous, igneous rock that forms during explosive volcanic eruptions. It is used as aggregate in lightweight concrete, as landscaping aggregate and as an abrasive in a variety of industrial and consumer products.
Rocks on Mars
June 13, 2013 | Geology.com
The Mars Rovers have helped identify a number of different types of rock on Mars. Many of the planet's rocks are similar to the shale, conglomerate, basalt and scoria found on Earth.
Thousands of Volcanoes in Arizona?
July 31, 2013 | Arizona Experience
Geologically speaking, Arizona is home to thousands of young volcanoes. Visit the Arizona Geological Survey "volcanic fields map".