Ether Cylinders, often referred to simply as cylinders, are items which house various forms of energy, and are a component in creating Gems. There are two primary types of Cylinders in Xenoblade Chronicles.
The other type of Cylinder available in gameplay terms is the type used to create Gems. Gems are items that equip onto Weapons and Armour to give players an additional edge in battle. The rank of the Cylinder determines the class (I-V) of the Gem, whilst the colour denotes the attribute. Cylinders posses only one attribute (like Strength Up, Muscle Up etc.) unlike Ether Crystals, which can have multiple.
Cylinders can be created throughout Xenoblade Chronicles by mining Ether Crystal deposits and then selecting "unused attributes" during the Gem Crafting process which did not turn into gems (at 100%). These Ether Crystal deposits are large, rocky structures that glow the colour of the element they are aligned with.
When players have collected all the Ether a specific area has to offer, they may return later to find the Ether restored.
Ether cylinders used in gem crafting are named according to their rank and the element of the Gem attribute they hold, for example Bright Wind Cylinder or Rare Ice Cylinder. The elements are Fire, Water, Wind, Earth, Ice, or Electric.
The first word of a cylinder's name always indicates its rank, while the second denotes the element of the Gem attribute it holds. So, for example, a Rank II Cylinder with a Gem attribute of Agility Up would be a Large Wind Cylinder.