A few things I have noticed, and which have come together to form an idea:
Robin Hopper, in his book “Making Marks” mentions the use of bones as stamps. He also says some are very brittle, so he has a “collection of animal bones” fired up to cone 10 to harden them. Cone 10 is well hotter than any firing I do; this suggests bones would survive my own glaze firings.
There was a Ceramics Monthly article a few years back, about an artist who presses rubies and other gemstones into her pots. The clay cracks around the pots when it shrinks in firing, but tends to hold the stone in place all the same.
There is a Discworld book called “Hogfather”, which, among other things, features tooth fairies, and teeth, and how you can use such things to change the world. Indeed, to end the world.
I have, somewhere in my apartment, a small jar full of my baby teeth.
Putting these things together could make a delightfully creepy teacup.