George Switzer, a scientist who acquired the Hope Diamond for the Smithsonian Institute and examined samples brought back from the moon by Apollo astronauts, died Sunday at 92.

Switzer once transported the diamond alone and unarmed to Paris for an exhibition in 1962, saying later that “secrecy was my only protection,” said his son, Mark Switzer.

“I was 11 and it was a big deal, you know, because flying across the Atlantic was still a big deal and Mom sewed up this little cloth pouch and they safety pinned the pouch and the diamond inside his pants pocket,” Mark Switzer said. The trip almost made his father believe in the bad luck stories that surround the diamond, Mark Switzer said, noting the original flight his father planned to take to Paris plane was canceled when the plane was damaged while landing in Philadelphia and the car he was riding in from the airport in Paris was involved in a minor accident.

Switzer’s efforts to develop a major gem collection were rewarded in 1958 when New York jeweler Harry Winston gave the Smithsonian the Hope Diamond, one of the most popular items at the museum.