The Starstone is a fictional item in the Marvel universe which first appeared in 1973 in issue #7 of the Marvel Premiere series of comics.
The 'Starstone was a football sized oval gem that was cold to the touch, as if it had been touched by the frigid cold of space. Within it was a strange shadow and those who touched it felt a chill of terror down their spines. Kathulos sent it to Earth, and when it was bathed in the light of the stars and moon, power was transmitted to the gem.
It was able to cast a spell on the inhabitants of the nearby town, controlling its inhabitants into drone-like slaves. From it a sentient slime came out which turned the Witch House into a living building that tried to kill its trapped inhabitants (by animating objects and overwhelming them with the flowing sentient slime).