Hutton clearly established the status of granite as a crystalline plutonic ... soon realized that not all granites are necessarily of igneous origin. Some occurrences were seen to have no sharp ...

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 ...

Intrusive igneous rocks are formed by magma that has cooled slowly, deep underground. Granite is an intrusive igneous rock. Granite has large crystals which can be easily seen with the naked eye.