This tiny lump of volcanic rock, in which some claim to perceive a female figure, could be the oldest work of art in the world, or it could be a tiny lump of volcanic rock. Archeologist April Nowell of the University of Pennsylvania recently tried to settle the debate about the 233,000-year-old stone, found in Israel 15 years ago. "It's really not that impressive," admits Nowell. "When I first saw it in a journal, I was pretty sure it was just a rock." To find out if the grooves on the rock were created by natural processes, she compared the "figurine" to other volcanic rocks from the area under an electron microscope. The grooves on volcanic rocks are usually parallel, Nowell observed, and only on one side of the rock. None of them encircled the rock like the groove that makes the neck of the figurine. Grooves in volcanic rock also have gaps and microfoldings, signs of rapid heating and cooling. The neck groove had none. The microscope also revealed tiny striations, like those made by a stone tool. Nowell concludes that the rock was modified by someone, most likely Homo erectus, wielding a stone tool. But it's difficult to say if the carver was consciously forming a human shape or merely scratching at the rock. If the rock is indeed a form of artistic expression, then archeologists have to fill a gap of nearly 200,000 apparently artless years that follow. "It's idiosyncratic, it's interesting, it's anomalous," says Nowell. "And it's definitely going to make us do a lot more research."