Igneous rocks form when magma cools underground or erupts at the surface as lava. The magma rises into the Earth’s crust, where it can get trapped underground or erupt from volcanoes as molten lava.

Like other igneous rocks, the glossy glass originates from molten rock that has been spewed out from the bowels of the Earth via volcanoes. Before we get into the snowflakes, obsidian is formed ...

From arachnid-like formations and mysterious blobs to an underground ocean and a giant volcano, here are our 10 favorite things scientists discovered on Mars this year.

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology. Laura is an editor and staff ...

The caldera is the enormous volcanic crater left from the ... Earth's molten core rises up through the solid rock of crust, heating and melting it to form reservoirs of magma 2½ to 30 miles ...

Melting ice sheets are often considered synonymous with climate change in the media, with evocative images of lone polar ...