Gem of Seeing

Powerful gem capable of fast casting True Seeing.

Acquisition
It's one of the new items in, obtained during Rasaad's Journey sidequest as a reward for passing the Blinding sun trial in Heretic Temple.

In-game description
"This finely cut and polished stone is indistinguishable from an ordinary jewel in appearance, although a Detect Magic will reveal its enchantment. When gazed through, the gem of seeing enables the user to detect all hidden, illusionary, invisible, astral, ethereal, or out-of-phase things within viewing range, as though  were affected by a True Seeing spell."