To bolster their strength, the Grand Companies of Eorzea seek donations of rare items. Accepted items are those which are sellable, and whose names are not yellow in their help window. Aetherial gear is an example of such.
If you wish to make a donation, speak to a Grand Company quartermaster to complete the delivery. You will be rewarded company seals for your contribution.
Closest Aetheryte: New Gridania
