[Quiet Man Cometh]

It was Eol. I just looked it up in CoH. Eol made two swords, one that he gave to Thingol as payment to live in a particular area, and the other was stolen from him by his son. Apparently he was not such a nice guy, in heart as Meilan says, and so the sword is also not so nice. Beleg took it when he went to go look for Turin and it indirectly caused his death. Turin took it after that just before all the supreme nastiness descended. He fought Glaurung with it (finally looked up the silly dragon's name). Maeglin didn't feature in that book though so I'm not sure what's up with him.

And yeah, the sword was made of meteorite and could smash any earthen iron, or so it's said.