Janus VI

Janus VI is an class F planet in the Janus system and home of the silicon based Horta who name their world Shaul (ST reference: The Worlds of the Federation)

The planet is rich in minerals, including Pergium, a energy source for thousands of Federation worlds. This prompted the establishment of a mining outpost in the 2210s. The federation miners remained unaware of the native Horta until 2267 when after new levels of the mines were opened the Horta began to attack miners in response to them destroying her eggs. The situation was eventually resolved and Horta and other federation personal now live side by side with the Horta later joining the federation. (TOS episode: The Devil in the Dark)