Gem of Seeing

Wondrous item, major, rare (requires attunement)

• Weight: 1.0 lbs.

This gem has 3 charges. As an action, you can speak the gem’s command word and expend 1 charge. For the next 10 minutes, you have truesight out to 120 feet when you peer through the gem.

The gem regains 1d3 expended charges daily at dawn.

Source: Dungeon Master’s Guide p. 172. Available in the SRD