Unusual

is a quality for equipment that has a special particle effect. Couriers are the only type of equipment that can be Unusual, and can only be obtained at a 1–2% chance through opening certain Treasures.

Effects
An Unusual courier's effect is defined by the Ethereal Gem that is placed inside it.

Colors
The color of most Unusual effects can be altered by Prismatic Gems.

Socketing
Unusuals come with one Ethereal socket and one Prismatic socket. Ethereal and Prismatic gems can be extracted with a Master Artificer's Hammer and placed on a different Unusual courier. Using a Master Artificer's Hammer will destroy the original courier. Inserting a new Ethereal or Prismatic Gem will overwrite the current one.

Greevils
Unusual Greevils are hatched from Greevil Eggs infused with Unusual Essence, and have their own unique effects, depending on the essences used. Greevils do not have Ethereal or Prismatic gems.