For an introductory collegelevel physical geology class: a review of how to classify and identify an igneous rock. Includes a discussion of the compositions ultramafic, mafic, intermediate, and felsic; and the textures phaneritic, aphanitic, glassy, frothy, pyroclastic; also reviews the naming process for porphyries and pegmatites, including identifying and naming the phenocrysts (and sorting out all these different terms!). Covers the following rocks: peridotite, gabbro, diorite, granite, basalt, andesite, rhyolite, obsidian, scoria, pumice, and volcanic tuff.

**This video comes near the middle of the semester, so there may be terms with which the audience is unfamiliar. For a full playlist, refer to the Geology playlists on the Earth Rocks! YouTube Channel.

Content within this video is based on information available in any standard introductory college geology textbook (or lab manual), such as Essentials of Geology Tarbuck and Lutgens Pearson Publishing.

If you are an earth science enthusiast and would like to support our ongoing video development and engage with us behind the scenes...
Or if you are a student and would like access to interactive lessons built around these videos...
you can do so by JOINING the Earth Rocks! YouTube Channel:
   / @earthrocks  .
Thank you!