mysterious items in arch mage's quarters

[pshred]

Hi ppl

i just became the arch mage of the mage's guild

and i found a locked chest named "runed ornate chest" and it doesnt say what the difficulty of the lock is (is it bugged?)

and i also found a hidden small jewellery box containing "glowing key", even after becoming arch mage, taking the items inside the box makes them marked stolen

so, what are these two items? what are they for?

Thanks