Do an image search for "antique woven hair jewelry"—it was a very big thing in Victorian times, especially for mourning.
Years ago I inherited a watch fob chain made of blond hair that I didn't recognize for what it was—probably a courtship gift from my grandmother to my grandfather, who always had a pocket watch—and thought it was "hairy" without realizing it was literally hair, and I tossed it. Could kick myself.
I believe those who made the jewelry for other than mourning collected their hair from their brushes. They used to make special containers for it to sit on the dressing table. Of course, all the women had very long hair in that era, done up in a loose bun on top of the head. I suppose they had to comb the loose hairs together the same way people do who weave sheep's wool to make yarn or fabric--I think they call it "carding."
One thing I noticed when doing the image search is that with the hair jewelry for mourning, you would expect most of the examples to be gray or white hair, but surprisingly many are of brown hair. One surmises that the deaths of younger people would hit the mourner harder and give more impetus for making the necklaces, brooches, or bracelets from their departed loved one's hair.
One of the reasons to collect your own loose hair was to make a hair bun stuffer for their pouf hairstyles.