In the reign of the emperor Tiberius (14-37 AD) a Roman glassmaker demonstrated a remarkable new glass at the imperial court. Unlike ordinary glass, it did not break: it must have seemed almost supernatural. The event was recorded by contemporary writers Pliny and Petronius. They called his glass vitrum flexile (flexible glass). The craftsman displayed a beautiful transparent vase to the emperor and then dashed it to the ground. According to the story, it dented but did not break. Tiberius asked if the glassmaker had told the secret of unbreakable glass to anyone else. When the answer was in the negative, the emperor had the unknown genius put to death and his workshop destroyed fearing that the new material would reduce the value of his imperial gold and silver.