A guide on how to create materia and attach it to your gear to increase its stats.
Overview of Materia
Materia are items that can be attached to gear to increase certain stats of the gear. Your gear accumulates spiritbond as you earn EXP, and when the gear reaches 100% spiritbond, you can convert the spiritbond into materia. You can then attach the materia to gear to increase its stats.
How to Unlock Materia Creation
Materia Creation, also known as Materia Extraction, can be unlocked during the level 19 Main Scenario Quest Life, Materia and Everything. During the quest, you will go to The Bonfire in Central Thanalan and talk to Mutamix Bubblypots. After a cutscene, you can talk to Swynbroes to accept and complete the quest Forging the Spirit to unlock Materia Creation.
How to Create Materia: Spiritbond
When you earn EXP or perform actions that would earn EXP, your gear also earns experience in the form of Spiritbond. When Spiritbond reaches 100%, you can convert the gear's Spiritbond into Materia, which resets the Spiritbond of that piece of gear to 1%. Prior to patch 5.2, gear was destroyed when you extracted materia from it, but this is no longer the case.
If you go to Main Character > Actions & Traits > General, you will find Materia Extraction, which you can drag to a hotbar or assign to a crossbar, or just execute from the Actions & Traits menu. This allows you to view the Spiritbond of the gear you have equipped, and any gear in your Armory Chest and inventory. You can select gear that has 100% Spiritbond and choose to convert the Spiritbond into Materia. Again, this does not destroy the gear; it just resets the gear's Spiritbond to 1%.
How to Affix Materia: Materia Melding
When you complete the "Forging the Spirit" quest mentioned above, you will then be able to talk to Materia Melder NPCs in city-states and hub cities and pay them to meld Materia to your gear.
Or, if you have a crafter at level 19 or higher, you can talk to Swynbroes after completing Forging the Spirit, to accept and complete the quest Waking the Spirit. This unlocks Materia Melding. You will be able to meld Materia into gear if you meet the Materia melding requirement of that piece of gear. View the gear's information window and look for "Materia Melding" to see the requirement.
Advanced Materia Melding
When you reach level 25 in any class, you can talk to Mutamix in Central Thanalan again to accept and complete the quest "Melding Materia Muchly". This unlocks Advanced Materia Melding, which allows you to attach Materia to gear even if all of its Materia slots are full; however, a given piece of gear can only hold up to five total Materia, and some gear does not support Advanced Materia Melding. The success rate of Advanced Materia Melding is much lower than that of attaching Materia to normal slots.