The 2008 movie, Indiana Jones and the Kingdom of the Crystal Skull, sparked a resurgence of public interest in objects that have long fascinated archaeologists and historians as well as spiritualists, New Agers and all the rest of the lunatic fringe.

Just what is it we are talking about when we discuss crystal skulls? Depending on who’s talking, and their name is legion, crystal skulls seem to be all things to all people. Are they genuine meso-American artifacts? Communication devices left by beings from outer space?