If you're engaged couple Matt Harrison and the improbably named Harriet Harriss, you go to the dentist and have him forcibly rip out your back wisdom teeth. Then you ask him to slit open the pulsating flesh at the back of your jaw and rip out a piece of your own skeleton. You then bring it to a lab and ask the scientist to dissolve it in chemicals, then feed the bone cells with nutrients and grow it into "bioglass" wedding rings.
It's not really quite that morbid, and Harrison and Harriss are no goths. They view the rings as ethical ivory. "It's intriguing to have my own bones, my own matter objectified in this way and made into something precious and symbolic," Harriet said. Although I can think of a better way to make a symbolic gesture than pay some butcher to rip out a huge chunk of my own skeleton.