If you're looking to add a bit of Trekkie geekery to your everyday attire, this might be the piece for you! As a member of Starfleet, every officer wears a badge. This one is worn by officers who work in command (e.g. Kirk, Chekov, Sulu).
Medical:
https://www.shapeways.com/product/DDLPXHKW2/star-trek-starfleet-medical-pendant
Science:
https://www.shapeways.com/product/8JAS5S2EG/star-trek-starfleet-science-pendant
Engineering:
https://www.shapeways.com/product/HZX3BTNWV/star-trek-starfleet-engineering-pendant