Mismatched Earrings

There is a custom in China, when two friends (girls) meet, to exchange an earring.
Something like our America's own friendship bracelets and necklaces, these mismatched earrings represent keeping the other person with you. I shared this custom with an acquaintance on my first visit to China, many moons ago. I have sadly since lost my mismatched pair. Hook style earrings have a nasty habit of slipping free and down sink drains. Whoops! I always thought this a sweet gesture but I think it needs to be the right friend, the right pair of earrings - a pair of earrings is not easily separated (one does not simply walk into Mordor with a pair of mismatched earrings). To make matters more difficult, many of my dearest friends do not have pierced ears. I entirely respect that decision or, in the case of my dear Belle, it cannot be helped (one lobe is slit due to a mistake in the piercing). Well then, what tokens can we carry as a symbol of our friendship? Belle and I have matching Cardinal jewelry (a pin for her, earrings for me). Pocahontas and I have our unique customs and greetings but no tangible symbol. Anne of Green Gables asked Diana Barry for a lock of her hair but...that's unhygienic and difficult to carry about (outside of a vintage locket). Rings are somewhat out of the question too. I don't have enough fingers left, what with a wedding ring, engagement ring, claddagh, and family heirloom. Suggestions are welcome.