Koh-i-Noor

The Koh-i-Noor (English: Mountain of Light) was a Piece of Eden in the form of a diamond that bridged all other Pieces. It was also rumored that only women could control its power.

During the early 19th century, the Koh-i-Noor was in the possession of Ranjit Singh, the founder of the Sikh Empire. It was stolen in the year 1839 by the Assassin Arbaaz Mir, it was destroyed by the Templar General Cotton. The Koh-i-Noor shattered, though Jot Soora currently holds on to a piece of the Koh-i-Noor embedded in his engagement ring. It is unclear what happened to the remaining shards of the diamond. The famous jewel that resides with the Crown Jewels of England is not the true Koh-i-Noor, but a replica.

Precursor Statement
When Princess Pyara Kaur used the Koh-i-Noor against Cotton, she became possessed by an unidentified member of the Precursor race. The being spoke to the assembled congregation:

"We are one of many but essential to the unity of all. Splintered though we may appear within the limited notion of this moment, we exist as one, as we always have and always will. You have been fragmented, children, but know that you are also whole.  Do not allow your concept of time to act as a paralyzing veil when the fate of all you hold dear rests in your hands.  We speak through this vessel to you, this time and medium and anchor that we might commune.  We must exist freely at all points for your race, our children, to exist and to remain free.  Shroud this intelligent lens until you become united and can realize this heart, our heart, to be the one that endowed your precious breath."

It is unclear if this statement is meant to address Jot Soora, the other Pieces of Eden, or all of humanity in general.

Reference

 * Assassin's Creed: Brahman