What is the bone dust for in aq worlds

Location: Various
Price: N/A (Dropped by Undead monsters)
Sellback: 0 Gold
Description: This reagent is probably usefull for something.
Note:

• 50x Bone Dust are required to enter Tercessuinotlim from Citadel
• Used in Bone Dust Reagent
• Used in Bone Dust Reagent

Thanks to mturf.