It's the caffeine molecule, of course. I intend to gift this to my former colleagues at Cranbrook Upper School. We have a K coffee machine there. Fun for the Science department and requiring explanation for everyone else, I suppose. I highlighted the molecule itself after printing with a gold pen form Rustoleum.

This object was made in Tinkercad. Edit it online https://www.tinkercad.com/things/kVZtWLQdTYE