Frostmourne's Winterheart

Frostmourne's Winterheart is a longsword carved from blue-white glacier iron around a translucent shard of ancient ice. Snow spirals endlessly inside its blade, though the weapon never melts or grows dull. Its crossguard resembles two frozen antlers, and seven pale runes glow along the fuller like stars beneath polar ice. The pommel contains a tiny trapped aurora that shifts color whenever the sword becomes angry. The hilt is wrapped in white dragonhide, cold enough to numb bare fingers.