The Artifacts were extremely powerful force field generators, which when linked together exonentialy inceases the size and strength of the generated forcefield.
They appeared in Raze 2.
The Artifacts are of unknown origin, presumably the aliens. The Raze 2 Human Campaign revolves around the discovery and placement of the four artifacts to create a forcefield to protect Earth. The Alien Campaign revolves around their attempt to take back the artifacts to protect the Aliens' homeworld.
The Humans used it to generate a forcefield to absorb the impact of the Asterid that threatened Earth in 2125. The generated forcefield exonentialy inceases in size and strength when the artifacts are linked together.