The extraction of items is a important part of the crafting system in Cabal 2, without the essences, which can be acquired from extracting items, crafting is not possible.

There are different types of rarity for essences just like the normal equipment. While basic/inferior essences can be used in alchemy to create medium/average essences (10:1) the higher tiers are only acquired by extracting gear.
On extracting an item you will always recieve an essence that is one tier below the extracted item:

Legendary Item > Heroic Essence
Heroic Item > Rare Essence
Rare Item > Magic Essence
Magic Item > Basic Essense
Basic Item > Basic Items cannot be extracted

Another important thing to keep in mind is that each type of item can only yield specific types of essences!

Research on “Back” extracting is not yet finished.