The veneration of relics is one thing many religions can agree on. From Buddha’s tooth in Sri Lanka to St. Anthony’s tongue in Italy, the faithful flock to witness—and worship—the bodily remains of holy figures, through which the grace of some higher power is believed to flow. Hair has always been one of the more abundant relics: It is easily harvested and a person generally has a lot of it, a fact which prevents awkward questions arising about authenticity. (In the Middle Ages, it emerged that a dozen different churches claimed to be in possession of Jesus Christ’s foreskin.)

Hair is also one of the few relics that has retained its currency in secular circles. In the Victorian era, preserving the hair of loved ones became a popular pursuit: Families would weave their tresses into mourning wreaths. Nowadays we have more high-tech ways of remembering our dearly departed, but the veneration of hair has once more shifted shape—this time into the lucrative celebrity memorabilia market.

At online auctions, famous hair can (and frequently does) sell for upwards of $100,000. Its valuation follows a similar logic to that of art: The death of its maker ups the value, as does any connection to an important biographical event. So, just as Van Gogh’s most famous self-portrait is the one he painted after cutting off his ear, Michael Jackson’s most prized hair clippings are those collected after he accidentally caught on fire when filming a Pepsi commercial in 1984. Before rolling your eyes at the worship of celebrities in place of saints, spare a thought for the researchers who have reaped the benefits of this unusual hobby. Without the ghoulish fans who snipped Beethoven’s hair as he lay on his deathbed, 21st-century scientists would never have been able to test the great composer’s locks and reach the intriguing conclusion that he died of lead poisoning.