This looks like great fodder for a conspiracy theory or at least a SF story. Moon rocks are disappearing all over the planet. Scientists cannot find 5 moon rocks that were given to the state of Hawaii:
but it is not just in Hawaii, it is moon rocks generally that are disappearing. According to the above article:
“But Hawaii isn’t alone. Gutheinz said that only about three dozen of the 368 gift moon rocks given to countries and states can now be accounted for.”
So that makes 332 moon rock gifts stolen or unaccounted for, 36 left to go.
Some more articles about this strange phenomena: