Sapphire

A Sapphire provides Cold Resist +22% when inserted in shields or off-hands, +24 to Mana in body armor and headgear, and +4 to Minimum Cold Damage, +7 to Maximum Cold Damage in weapons.

A Sapphire requires level 12 to use. When you socket an item with a Sapphire, you increase the level requirement to level 12, unless it was already higher.