The Domus Aurea, or Golden House, was the sprawling palace of the Roman emperor Nero. Archaeologists recently uncovered a chunk of Egyptian blue ingot, an example of the opulence of the palace itself.
“The fascination conveyed by the depth of blue of this pigment is incredible,” says Alfonsina Russo, the director of the Colosseum Archaeological Park, which manages the Domus Aurea, in a ...