Sedimentary rocks are made up of pieces of older rocks (igneous, metamorphic, and sedimentary) and organic remains (shells, bone, etc.). When rocks break apart from erosion they are transported by ...

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 ...

THE closing years of the nineteenth century witnessed a revival of interest in the petrology of gneous rocks, which must be regarded as marking an important stage in the development of that subject.

Rocks and minerals are closely related, but there are fundamental differences between the two. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

This image is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. When we look at a rock, we often just focus on its size and appearance. Is it light or heavy? Dark or ...

THE magnetization of dated igneous rocks has been much used for the study of the directions of the geomagnetic field in remote geological periods. This method is based on the supposition that 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 ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This is a large piece of a type of ...