Watch an audio-described version of this video here: https://youtu.be/DO3VX7e1R7E Smithsonian geologist Ben Andrews introduces the three types of rocks — igneous ...

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 ...

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This video is audio described. Watch it with captions, but without audio descriptions, here: https://youtu.be/w-tXJkMI_Mw Smithsonian geologist Ben Andrews introduces ...