- Job Cards will charge a cost of Crystal x1 - 5 to unlock the final square on all Skill Panels. Usually this is an upgrade to a weapon, but this can also be a significant new Ability. These panels must be unlocked to continue to a Job's next skill panel. Most jobs will need Crystal x24 to complete all 8 skill panels.
- Job skill cards obtained from Hall of Fame costs 6 crystals each to equip.
- Weapon Modification requires 2 Crystals to complete a step. These will increase particular special abilities on a weapon, including Speed, Defense, and Crit Chance. Modifications are required (and special stats increase) once for every 6 increases to a weapon's basic stats (Attack, Magic, etc). Most weapons will take 40-70 such modifications before they reach maximum power.
Crystals can be obtained in multiple ways:
- They are a higher-value reward found in Treasure Chests near the end of most Regions; particularly Ranked Events at the Tower of Trials. Areas that drop these are shown with a Crystal-colored Treasure Chest in the center of the area spot on the Region Map. Almost every region will have at least one such area.
- Ranked events will typically include Crystals as a reward for placing on the event's Ranking List. While anyone within the top 10,000 players will get some Crystals, earning a higher placing will get a larger reward. 5-10 Crystals may also be awarded just for participating in the Ranked Event.
- Crystals drop as a Very Rare drop from most fiends, particularly Bosses. The likelihood of this can be increased by equipping jobs, weapons and Ability Cards with the Crystal Seeker Auto-Ability.
- Crystals drop as a Common drop from the Crystal Gigantuar, which can be found in the Pleiades Lagoon region as well as certain "crystal farm" areas in various regions.
- 5 Crystals are included in the Mobius Gift Box, which can be purchased every 30 days for Magicite x1,500.
- Crystals are typically included in the rewards for special promotional activities, such as Social Media Campaigns, Chapter Completion trophies, and Defeat the Sicarius events.
- Crystals can be purchased in the Item Shop in exchange for Magicite: 1x Crystal for 200 Magicite, 6x Crystals for 1,000 Magicite. Additionally, 9 Crystals can be purchased once every Monday for 2,000,000 Gil in the Item Shop.
"In addition, after the 10/1 (2019) update, drop rates for Crystals will increase when defeating the Crystal Gigantuar! You will receive up to a maximum of 3 Crystals! Due to the influence of the Crystal Seeker, the stronger your auto-ability, the better your chance at obtaining 3 Crystals! Hunt down those Crystal Gigantuars within Yggdrasil to gather as much Crystals as possible!"