The three types of rock October 21st, 2011 • Filed under: geology | humor Hah. My sister sent this to me. Related Posts This often happens… May 10, 2010 Video of Eyjafjallajökull eruption April 21, 2010 Everything’s amazing, nobody’s happy February 2, 2010 ← Previous Post Extrapolating the screen size of Android mobile phones over time. Next Post → Stop SOPA