Pumice is an example of extrusive igneous rock. The word extrusive means that ... In this picture a geologist uses a pick ax to yank a piece of lava from the overflow. Why is it important to ...

NASA has found a rock on Mars that it has dubbed Skull Hill. The rock is known as a "float rock," and NASA has no idea where ...

Marble is a metamorphic rock, it is highly decorative and used for statues. Igneous rocks are formed from molten (liquid) rock that has cooled and solidified. The inside of the Earth is so hot ...