The travelers purchased what was described as an unusual rock weighing 274 kilograms in Kyrgyzstan, which the three described among themselves as a “glowing marvel.”

Upon their return home, the tourists decided to find out what their unusual souvenir was made of, and broke a piece of the rock off and sent it to geologists at Beijing’s Tsinghua University, who revealed that the power of the “glowing wonder” was depleted uranium and called the police straight away.

The souvenir was confiscated from the travelers, but the were not sent to jail for carrying contraband uranium, as it was clear they were in the dark about their glowing marvel, the Chinese Daily said.

All three underwent medical examinations at a local clinic and were found to be clear of radiation sickness, RIA Novosti reported.

But their close contact with uranium ore could result in other health difficulties. Uranium emits alpha radiation and alpha rays are especially dangerous should the radioactive substance be ingested. By-products of uranium decay, such as radon, also present dangers.