Guide:
Found inside Sandblown Mine solo dungeon, which is located in south edge of southeastern Alik’r desert. West of Tears of the Dishonored POI.
Once you enter the dungeon, keep going to your left. As you reach the farthest northeastern part of the mine, you should enter the small room with the shard inside. When you eventually find it, you’ll notice where this skyshard got its name from.