Fóstral

Fóstral is a fictional substance that appears in science fiction and speculative fiction. It is typically described as a rare, luminescent material with extraordinary energy density and unusual optical or reactive properties. Because Fóstral is fictional, its characteristics vary by author or medium, and there is no single canonical definition.

Origin of the name is varied; some authors derive it from fictional languages, others treat it as a proper mineral name. In many narratives, Fóstral occurs in isolated deposits within primitive planets, asteroid belts, or derelict ruins, and its extraction poses hazards such as spontaneous fragmentation or volatile reactions with air.

Applications within stories include use as a power source for starships, catalysts for advanced alchemy, or focal material for psionic devices. Its scarcity and difficulty of handling often drive plot points about trade, smuggling, or territorial control. Some works depict refined forms that can be processed into energy crystals or integrated into armor or weapons.

Fóstral has no basis in real-world chemistry or mineralogy; it is not recognized as a real element or compound by scientists. It is primarily a tool for world-building, offering a flexible set of properties to suit different science fiction settings.