Your Cold skills now always Chill monsters and slow their Movement Speed by an additional 5.0% for 3 seconds. You can only level this Gem to rank 50. Every upgrade will increase the slow effect by 0.4% up to a maximum of 25% total.
This Gem however, is mainly used for its secondary effect: 10% additional Critical Hit Chance debuff against Chilled or Frozen enemies. This effect procs itself with the primary Bonus as long as you use any Cold skill. This effect does not work for most Damage over Time (DoT) skills (e.g. Rend, Haunt) as their damage is calculated directly from the player’s sheet Critical Hit Chance and Critical Hit Damage. This effect does not stack with other players wearing this Gem.
Iceblink Best Use
Only used on Supports: Very common support Gem due to the huge secondary effect. This effect usually boosts the Damage Dealer by around one Greater Rift Tier.
Legendary Gem in Diablo 3
Legendary Gem Creation:
If you need extra Legendary Gems to level up, you can make the Rift Guardian in any Greater Rift drop a new Rank 0 Gem by removing all the Legendary Gems with the same name from your Equipment, Inventory and Stash.
The safest way to do that is to put them into the Inventory of different character.
