A spokesman for the Louvre Museum in Paris said the incident happened on Aug 2, when a Russian tourist threw a mug at Leonardo da Vinci's Mona Lisa, the world's best-known painting.
Paris police arrested the woman and was taken to a psychiatric ward afterwards.
"It looks like it was done by someone who was unhinged and wanted to draw attention to herself," a Louvre spokesman was quoted as saying by the AFP news agency.
The Louvre is the biggest art museum in the world. It has thousands of paintings, but its star attraction is the Mona Lisa, known in France as La Joconde.