Buyer beware. If you think you’re smart enough to outwit a forger, study this oil lamp carefully: The body is an authentic second-century C.E. Roman-era lamp, but the central disk is a fake. The tell-tale giveaway? The menorah and its flanking wreaths are both ancient Jewish symbols, but they appear together on synagogue decorations—never on lamps. If you knew that, you might feel confident enough to venture into the antiquities trade; if you didn’t, many a forger or unscrupulous antiquities dealer would love to do business with you.