I had a question for you all, seeing as I know little of weapons and even less about metals:

I was wanting a character to have a sword specifically made of Cobalt and bismuth for some blue color. What I've been looking for and can't find is the answer to the question: Is cobalt strong enough for a sword? Is it too heavy for a sword? Would it be a light sword? Would a cobalt sword just break when used?

Thanks in advance for anything you can give me to help me out.

You could actually have a steel blade, and then have it go through a process called "bluing" which is used for guns, but could probably be transferred to swords.

It wasn't so much the blue color I was concerned with, just that cobalt has a special meaning in the story, so I was wondering about cobalt.

Okay. Maybe a coating, but probably not a sword made from it.

Or could the hilt be made with it, maybe?

It might be, depending on how it's made. The pommel, at least, could be.

I have a similar issue in an upcoming fantasy story I have planned. The blades were originally going to be purely a certain material: Diamond, Emerald, etc. In order to avoid the impracticality of using those materials as sword blades, I use my original-created element to sort of reinforce it and keep the blade together and make it a viable weapon.