There are 50 Calcified Fragments to be found in Destiny: The Taken King.
This one can be collected on any mission or during patrol.
From the Rupture Portal, turn to the left. Head for the door in front of you, but do not go in it. Turn to the left. Jump over the railing and head inside the door on the right.
Inside this room you will want to turn to the left.
Go into the hole in the wall there. Turn to the left and jump up onto the ledge. Look to the right to find the Calcified Fragment
Book of Sadness Entry
Sisters! This is how an oath is done. Put your left hands on the mast, close to mine.
Take the knife in your right hand. Push it through your left hand, straight between the bones. Now! Carve a blood line down the mast.
Speak your oath.
“I am Xi Ro, youngest daughter of the dead king. I will take back my Osmium Court and kill the traitor Taox. On my left eye I swear vengeance.”
In blood the oath is made.
“I am Sathona, middle daughter of the dead king. I will take back my home and eat the mother jelly. I will raise my spawn on the corpse of the Helium King. On my right eye I promise this.”
"In blood the oath is made."
“I will help make your oath, sister.”
“I will help it too.”
I am Aurash, first daughter of the dead king. I will chase my father’s last screamed warning. I will know what changed the motion of our moons. If the end of the world is coming, I will understand why.
On my center eye I swear it. I will understand."
“In blood the oath is made.”
Thank you, sisters. We have only my ship left to us. But a ship is freedom! We have secrets to hunt, storm-lit realms to explore, and great armies to raise.
Put up the lightning sails, and we will voyage far.