`South African gold mine salt shaker smuggling`

Chemistry-lab worker smuggled gold out as gold chloride (visually indistinguishable from table salt) in his daily egg-and-salt lunch. Defeated metal scanners because gold chloride is not metallic.

My favorite story was not from Leach and Garner, it was from South Africa. One guy was working in one of the gold mines, in the chemistry lab. He brought his lunch every morning — he'd have a hard-boiled egg every day, with a little container of salt. He put it on his egg, and everybody knew that's why he had it. Then he started taking, instead of salt, gold chloride, which looks just like table salt. He could produce it in the lab, and it wouldn't show up on the metal scanners because it wasn't metallic. They finally caught up with him.