Wrought Iron and 15n20 san mai with a 3D printed high density ABS plastic handle.
I was a bit weary about the plastic (customer couldn't afford cast bronze or brass), but it's quite resilient... ask anyone that's stepped on a Lego.
Only flaw is it's TOO white; every speck of dirt on your hands is drawn to it like a magnet. I combated this somewhat with several layers of aerosol lacquer. The plastic weighs nothing even though it's solid and the tang runs all the way through the handle.
This project was a metric snotload of fun. It's based off my favorite monster, from my favorite video game