Thundereggs look like regular rocks from the outside, but contain intricate and colorful mineral patterns inside — often made ...

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 igneous ...

In my last column, I wrote about the locations where you can find igneous rocks that were formed from lava. The metarhyolite and metabasalt described in the column are known as extrusive rocks, those ...

There are three types of rock found on Earth. These are igneous, metamorphic and sedimentary. Each rock type is formed in a different way. For example, the rock malachite is mostly made of the ...

Scientists on NASA's Perseverance mission made a surprising discovery about the composition of rock in Jezero Crater, one that will help them get a better idea of when water existed on Mars, and ...

Both volcanic and plutonic rocks occur associated with the Martinsburg formation in Lebanon County. The area is located about one-half mile south of Jonestown and is approximately six and one-half ...