HARVARD MUSEUM OF NATURAL HISTORY
'(<a href="http://www.j-archive.com/media/2011-11-24_J_30.jpg" target="_blank">Sarah of the Clue Crew delivers the clue from the Harvard Museum of Natural History in Cambridge, MA.</a>)  Weighing in at more than 1,600 pounds, the giant chunk of amethyst <a href="http://www.j-archive.com/media/2011-11-24_J_30a.jpg" target="_blank">here</a> is one of these stones that form under pressure inside cavities, from the Latin for "earth"'
a geode