Gems that emit light during the day.
Aura Faint Evocation
Price 4,000 gp
Diurnals are small, coloured crystals that emit bright light (60ft radius the same colour as the crystal) while the sun is in the sky. As the sun rises or sets a diurnal will take 10 minutes to brighten to full power or fade to complete darkness.
Requirements Craft Wondrous Item, daylight; Cost 2,000 gp
Diurnals are commmonly used in underground places to keep track of day/night cycle.