Ruby bolts are adamantite bolts tipped with ruby bolt tips. Ruby bolts can be created at level 63 Fletching by first cutting a ruby into 12 bolt tips then attaching them to adamantite bolts to create ruby bolts. Each bolt tip and crafted bolt awards 6.3 experience.
Ruby bolts can be enchanted through the spell Enchant Crossbow Bolt (Ruby) at level 49 Magic. The spell enchants 10 ruby bolts at a time, and once they are enchanted they become enchanted ruby bolts and gain a special ability, the Blood Forfeit enchantment. This gives the bolts a chance of damaging the target for 20% of the target's remaining health at the cost of removing 10% of the attacker's remaining health. The enchantment will not trigger if the attacker is under 10% of their max health.