Menachite Forerunner crystal

A crystalline Forerunner artifact was discovered in an underground facility on Reach by Dr. Halsey and the surviving Spartan members of Red Team in 2552. The artifact is of incredible potential, capable of warping space, energy and even time. It is hardly understood by the UNSC forces who found it, but is a prize that the Covenant were extremely eager to obtain.

The Crystal is a fist-sized Forerunner artifact. When originally seen by Dr. Halsey and the SPARTANS in the underground facility on Reach it was floating upright and the area around it was distorted by gravity. The crystal reacted with a burst of neutronic radiation at Halsey's touch. When exposed to a Covenant gravity beam, the crystal nullified it, reshaping itself in the process.

When the Ascendant Justice jumped into Slipspace the crystal again rearranged itself, emitting radiation during the entire jump, and caused gravitational distortions. The location of the ship at the end of this jump was somewhere near the Eridanus system, a distance that from Reach should have taken several days instead of a few minutes. Comparing timestamps from several missions Dr. Halsey discovered a 3 week average difference. Her conclusion was that the crystal bent both space and time so that it could be removed from Reach by Cortana and the Master Chief. Halsey later gave the crystal to Corporal Locklear, who covered it with a C-7 explosive and blew it up to avoid another Slipspace radiation spike, accidentally killing himself in the process.

Three shards of the crystal were recovered by the Covenant, which were presented to the Prophet of Truth by Tartarus in an orb-shaped container, Truth then ordered the Brute to reward the pilots that had recovered them, then kill them. The UNSC also possesses pieces of the crystal.

The Slipspace that it projected when the ship went into slipspace is possibly a blue portal similar to the Portal found at Earth. It is probable that the Forerunners used this crystal or others like it to travel throughout the galaxy and past its edge almost instantaneously.

At the end of the book Halo:First Strike, Truth is given a handful of the crystals. He then says it may be enough to complete what they need. It is possible that the Ark on Earth may not open unless some piece of the crystal is present, as a final key to safeguard the location of the Ark to the flood.