Los Angeles: NASA on Saturday detained a woman offering to sell a moon rock for USD 1.7 million, the authorities said.

It is illegal to sell moon rocks, which are considered national treasures. The gray rocks, which were gifted to each US state and 136 countries by then-President Richard Nixon,
can sell for millions of dollars on the black market.

NASA agents and Riverside County sheriff's deputies detained the woman, who has not been identified, after she met Thursday with an undercover NASA investigator at a restaurant in Lake Elsinore, about 70 miles southeast of Los Angeles, the sheriff's office said on Friday.

They swooped in after the two agreed on a price and she brought out the rock, authorities said.

NASA had been investigating the woman for several months before the meeting. The space agency planned to conduct tests to determine whether the rock came from the moon as the
woman claimed.

"We don't know if it's lunar material," said Gail Robinson, Deputy Inspector General at NASA.

The woman has not been arrested or charged. It was unknown how she obtained the rock or came to the attention of NASA.