PoE2
Added Chaos Damage
Support
Chaos
Cost Multiplier: 120%
Requires: Level 1
Support Reqirements: +5 Int
Supports Attacks, causing them to gain Chaos Damage but deal Damage of other types.
Supported Attacks gain 25% of Damage as Extra Chaos Damage
Supported Skills deal 50% less non-Chaos Damage
Place into a Skill's Support Gem socket in the Skills menu to apply its effects to that Skill. You cannot have multiple copies of the same Support Gem socketed at the same time.
PoE1
Added Chaos Damage Support
Chaos
Support
Level: (1–20)
Cost & Reservation Multiplier: 120%
Requires: Level (31–70), (52–111) Int
Supports any skill that hits enemies.
Supported Skills have (18–154) to (26–231) added Chaos Damage

Additional Effects From Quality:
Supported Skills deal (0–10)% increased Chaos Damage
This is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Skill Gem you wish to augment. Right click to remove from a socket.