Candlerock

Candlerock, sometimes called glowstone, is a rare type of rock that produces its own light.

Properties
Candlerock is a crimson red stone found in the Cliffkeep Mountains and the Underdark beneath it. Candlerock is luminescent, producing a reddish glow.

History
Candlerock is used throughout the dwarven city of Kraghammer, though the Bottom Slab appears to use it less in favor of torches. The duergar of Emberhold also use candlerock to light their warcamps and Emberhold itself.

In The Legend of Vox Machina, Greyskull Keep is lit by luminescent stones, seemingly candlerock, held in torch sconces.