If you consider thousands of dollars for a tiny patch of decades-old mold a tad too pricey, well, maybe you're just not cut out for the high-stakes world of mold auctions. Because not even that hefty bit of green wouldn't have brought home the other bit of green that just sold Wednesday at a London auction house.

The mold in question — which actually outpaced early expectations to be sold for a whopping $14,617, according to The Associated Press — is a capsule of the original Penicillium chrysogenum Alexander Fleming was working with when he discovered the antibiotic penicillin. Encased in a glass disc, inscribed with the words "the mould that first made Penicillin," and signed by Fleming himself, the little sample comes from the collection of Fleming's niece, Mary Anne Johnston.

Penicillin eventually went on to revolutionize medicine, which by the 1940s was mass-producing the antibiotic to treat many bacterial infections. "Scientists at Oxford University further developed penicillin," the AP explains, "and production was ramped up so that enough of the antibiotic would be available for the Allied invasion on D-Day in 1944."

And Fleming himself, it seems, was also distributing the original mold far and wide. Called "mold medallions," little items like the one sold Wednesday were passed out to notable figures worldwide. Bonhams, the London auction house, says Pope Pius XII got one, as did Winston Churchill, Marlene Dietrich and the Queen Mother Elizabeth.

"These insignificant-looking artefacts soon took on the status of holy relics," says Kevin Brown, author of Penicillin Man: Alexander Fleming and the Antibiotic Revolution, according to Bonhams.

Fleming seems to have used the mold medallions as a combination annual bonus and hostess gift. As Quartz puts it: "Award Fleming an honorary degree? You got mold. Dedicated service in his lab? Mold. A special audience with a celebrity or royal? Again: mold."

And Prince Philip, Queen Elizabeth's husband, apparently received multiple copies.

"Every time he met Fleming, he got another one of these things," Brown tells the AP.

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