The Monolith Monsters

A giant meteor crashes to Earth near the small town of San Angelo, and a local geologist brings a fragment back to his lab for testing. Shortly afterwards, a fellow geologist shows up and finds the lab filled with rocks and his cohort cold and dead, his body turned to stone. In a desperate race against time and nature, he must unlock the secret of the deadly rocks from outer space before they blanket the world and destroy mankind. (official distributor synopsis)