Okay, maybe i'm just an idiot, but i still can't find my mistake. So let's check bungleaus list:
1. An artifact spell (you've got that)
That's right!
2. The Cabalist Trait
Yep!
3. At least one level in the Blessing skill
I have level 7.
4. An item that can be enchanted (some can't!)
They can be enchanted by other party-members
5. That item needs at least one less blessing or enchantment than your Blessing skill level
I tried items with one single enchantment and even a f*** trouser i bought in the store.
So what's the problem?
Is the artifact-of stone-spell the wrong one to bless armor? This character doesn't have other artifact spells right now.