Pumice is an example of extrusive igneous rock. The word extrusive means that the magma was forced onto the earth's surface and cooled in a matter of hours. Granite is an example of intrusive ...

Towering hoodoos—cone-shaped spires reaching up to 90 feet tall—rise from the earth, sculpted from layers of ash, pumice, and tuff. Kasha-Katuwe Tent Rocks National Monument, whose name ...

If something seems light for its size (like a bag of cotton or pumice rock), then we say it has low density. Mass is the amount of matter in an object. Volume is how much space the object takes up.

She was about 20 years old; he was in his mid-40s. A violent downpour of rubbly pumice mixed with incandescent rocks capable of crushing skulls and scalding skin obscured their escape. To their ...