salvaging weapons...

I'm sure this question has been answered a million times, but since the search function is not working, I'll ask again:

Why is it some weapons cannot be salvaged? I have a "poisonous longbow" that cannot be salvaged, and a "Barbed Ascalon Razor of Charslaying" that cannot be salvaged. The second is customized for me.

I am using an expert kit, and there are quite a few other examples, I'd say I have a dozen weapons that can't be salvaged, and I know some were drops and not quest items.

Quest reward weapons are not salvageable. Those are both rewards. I'm not sure, but I don't think greens are salvageable either.

Green items and quest items can not be salvaged
Was it a quest item?

collectors cant be salvaged eitehr