I've turned in a variety of 20 exceptional shadow helmets: norse helms, bascinets and helmets. I always got a dull copper hammer, I think a fair exchange for few hundred shadow ingots. This morning I got studded gloves. Bah! Of course there's a range of possible rewards, but as low as studded gloves? I just sell them back to the NPC when I next get orders. You can't even give them away to anyone but newbie miners.
I suppose I've enough dull copper runics for my everyday weapons, anyway. From now on I'll give these orders to my friend for his faction smith (let him risk the ingots :/).