Iris gems and Item Fusion
All magic items are made up of four primary conductive elements: Earth, Air, Fire and Water. These 4 “slots” can hold different special attributes and properties that further enhance magic items. An item can be made with up to four different properties, one in each element slot.
Iris Gems are a special kind of crystal that stores a specific magical property. Each iris gem is dedicated to Earth, Fire, Water or Wind. An enchanter of proper skill can take an iris gem and permanently fuse it to an item. When this does so, if there is an empty slot of the appropriate element, the gem is lost and the item permanently acquires that attribute.
If the slot is already filled with a property and you attempt to fuse another attribute into it, one of two things will happen. If both properties are the same, the property will upgrade, into something more powerful. If they are both different, the magics will warp and something new will emerge.
An enchanter of appropriate skill can also disenchant a magic item, removing the iris gems from them completely. However this process will remove all the magic from the tiem, making a mundane object once again.