I was only wondering if there is any pure magical weapons in NWN, exept for those you enchant at the smitty. I mean weapons like the daystar and Holy anvenger.

in case there are, which kind of magical weapon is the most common.

yes there are. in the manual, it says that there is white dragon scale (good luck), Angurvadal or flame blade, and stars of Ojy-do. those are a few examples of the unique magical weapons in the game.

Actually, that white dragon armor is a smithy item.

Yes, there are lots of named magical items in the game. Most of them are not unique, but you'll find a few that are.

I've found the white dragon armor in a chest on Chapter 2 somewhere.

I'm not sure, but I think every weapon in the game you can view from the "items" tab if you open up the toolkit that comes with the game. I've heard (here) that if you have weapon focus or specialization in something the computer will send more of that type your way. You'll probably find all the smithy items in chests sooner or later too.