Ruby

Ruby is one of the 8 Infusable gemstones. It can be infused by laying it exposed to completely uninterrupted sunlight for 8 hours. Since this almost never happens on Tara, pretty much all infused Rubies are imported from Barren Grayne. Infused, they have a variety of uses:
 * Herblore: makes the drinker emit light.
 * Weapon: burns Undead.
 * Self-Infusion: grants immunity to temperature.
 * When used in a machine, makes the machine emit a faint light.
 * When an Infused Ruby is tapped by an infused Diamond, the latter loses its Infusion and the Ruby shines with a bright white light. Is regularly used for lanterns by the rich.