The headline says it all: Terracotta army has egg on its face. It would appear the paints used on the famous Chinese terracotta army were egg-based, which made them far more durable than ancient water-based colors.
When you see things like this, don't gasp in wonder. Gasp at the waste. Yes, it's amazing, but in a very real sense these emperors and kings were spending bread money to put men on the moon. Except the Apollo program never came close to a majority share of this country's budget. The ancient world was so poor follies such as mountains of stone pointing nowhere, and clay pot armies buried for no reason, almost certainly were.