Gem Hammers can only be used out of combat and will add a gem socket to the weapon. The amount of Gem Hammers needed to add a socket depends on the weapon (normal/legendary) and the amounts of sockets already added to the weapon:
Socket Number | Gem Hammers Required |
---|---|
1st | Free |
2nd | 1 Gem Hammer |
3rd | 1 Gem Hammer |
4th | 3 Gem Hammers |
5th | 5 Gem Hammers |
6th | 8 Gem Hammers |
Note: Upgrading Legendary weapons requires Legendary Gem Hammers.