Fragment of Elder Starlight

This smooth, egg-shaped crystal is about 6 inches tall, weighs 3 pounds, and sheds bright light out to 20 feet and dim light for an additional 20 feet. The light is sunlight. You can touch the crystal and mentally control its brightness as a bonus action to enlarge, reduce, or snuff out the light’s reach up to its maximum range.

While holding the crystal, you can speak its command word as an action to cause it to release a wave of bright light. The wave of light washes over creatures not behind total cover within a 60-foot radius from the crystal. Undead creatures and fiends affected by the wave of bright light must make a DC 16 Constitution saving throw. On a failed save, a creature takes 8d6 radiant damage and is blinded until the end of your next turn. On a success, it takes half as much damage and is not blinded. Friendly living creatures of your choice within the wave of bright light regain 4d6 hit points.

Once this property of the crystal has been used, its light dims and can’t be used again until the next dawn. While its light is dimmed in this way, it sheds bright light out to a maximum of 10 feet and dim light for an additional 10 feet.