There are 50 Calcified Fragments to be found in Destiny: The Taken King.
This one can be collected on any mission or during patrol.
Fragment 6[edit]
Head into this small doorway near the passage between the Mausoleum and the Hullbreach (on the hullbreach end). This is the same passage that Calcified Fragment V is found in.
This leads to a small passage. Head to the left inside the door and then follow the hallway to the right. Hang to the left and enter the hole in the far wall.
It is something of a maze. When you reach the first intersection, go straight ahead.
Make a left at the small pillar.
Turn right at the next intersection and follow this to the room it leads to.
Head into the back left corner of the room. You will find the Calcified Fragment sitting here.