Woodwork/Metalwork: Envelope Opener

This is my latest project. I started by experimenting with hardening steel. I made a few carving chiesels that I hardened with a simple process (let me know if you are interested in more details). The carving knifes ended up pretty hard and sharp. After that I had to try something more challenging and I ended up working on this letter opener. I started with this material:

From the top to the bottom: A piece of steel (not the highest quality unfortunatelly), a piece of Purple Heart and a piece of American Black Walnut. I don't have any photos of the various stages (next time!), but here is the result after about 4 hours of cutting, polishing, carving and finishing.
Here it is closed:

Here it is opened:

A detail of the purlple hart and Black walnut handle:

Ok, perhaps is a little too sharp to be used as an envelope opener. I think it will function better as a fancy rough carving knife...

Eventually I'll put some filework on it, but I've never done it and I need to experiment on something else first.