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 ...

THE discussion on this subject arranged by the Faraday Society excited great interest, and the collected papers contain much that is of value. Whilst most of the speakers dealt with heterogeneous ...

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 ...

THE potential of the potassium–argon technique in the dating of young rocks can be evaluated by applying it to intrusive igneous rocks which are well dated by conventional geological methods. Because ...

I’ve been thinking about granite a lot recently; primarily because we have been covering plate tectonics in my AP Environmental Science class. Granite figures prominently in this discussion because ...