In a new update for Final Fantasy XIV: Stormblood, the Adventurer in Need bonus for Duty Roulette: Leveling now provides a Cracked Cluster, although the UI won’t indicate such until a subsequent update.
Upon earning a Cracked Cluster, you can turn it in at Switchstix, an NPC near the middle of Rhalgr’s Reach, Gyr Abania. He’s located at the coordinates (X12.5, Y11.3).
When turning in the Cracked Cluster, you will be able to choose from a wide assortment of level VI materia. It is recommended that you choose whatever is valued the highest on the Market Board. Even if you’re looking to use a materia, selling it may allow you to buy two or more of the type that you need.
Due to this addition, the value of level VI materia is quickly dropping across all servers. We also recommend that you sell your materia as soon as possible, as their value will likely drop significantly in the next month or two before achieving market equilibrium.