The Black Tetrahedron is a crystal of unknown origin. It Part 9 – The Lost Colony was discovered in a Saurian laboratory. This laboratory appeared to have been used for experiments on dimensional gates, leading to the possibility that the Tetrahedron may have come from another dimension.
Meditating on the crystal seems to raise one’s awareness, making the person’s mind capable of understanding complex and abstract concepts that their mind would not normally grasp. However, using the crystal also seems to create a link to Nyarlathotep, the Crawling Chaos.
The crystal was dropped into the Caspian Sea around 600 BC.