As far as I know this sword is unique:

Here's what it looks like:

As you can see it is a style of sword that is unlike any other sword in the game, craftable and otherwise. I believe this is a reward for doing a quest in Craglorn, but I thought it was odd that a random quest reward would have a completely unique skin.
If anyone has some greater insight into this, I'd love to hear it. Is it perhaps a sword with significance to certain Elder Scrolls lore?
"Madness is a bitter mercy, perhaps, but a mercy nonetheless."
Fire and Ice