The sphenoid bone is a butterfly-shaped bone in your head. It makes up the bottom half of your eye socket and is hollow. If you’ve ever had a cold and experienced pressure in your face, that’s because your sphenoid sinus, aka that hollow space in the sphenoid bone, is filled with mucus. Out of all the head bones, this one is the only one that looks like something out of a Rorschach test. It was only fitting that we turn it into a necklace. Purchase it as a gift for yourself or buy it for a friend. This necklace would make an excellent surprise for boxers, singers, ear/nose/throat specialists, and those starry-eyed pre-med students.