Guide:
Southwestern central Malabal Tor, south of Dra’Bul Wayshrine.
Shard is inside Tomb of the Apostates solo dungeon. Dungeon’s entrance is covered in vines and you best approach it from north. “Ancient Scrolls of the Dwemer I-B” lorebook is near the entrance. As you enter the dungeon, turn left and go toward the area with lots of water. It is located inside this space.