The Slipspace core, also known as the Source Crystal or the Mother Crystal, was a large, quantum-engineered crystal used by the Forerunners to create slipspace drives for their ships. Pieces were chipped off from the core crystal, transported to manufacturing facilities all across the ecumene and then cut into smaller flakes for use in new slipspace drives from the smallest craft to the largest. The exotic composition and slipspace interactions of the crystal were incomprehensible to even the Forerunners, and never replicated. Befitting its importance, the crystal's location was one of the best-kept secrets in the ecumene. It was said that only the Master Builder knew the location of the core. 343 Guilty Spark stated that only the cutters knew and they would have rather died than reveal its location.
In 2557, Guilty Spark took the salvager vessel Ace of Spades to the Forerunner world of Triniel to acquire a flake of the crystal to help upgrade the ship's systems. The crystals were so dangerous that Spark could not allow them to be salvaged nor could the humans touch them.
List of appearances