fastidia

Fastidia is a fictional mineral used in speculative geology and worldbuilding to illustrate properties of dense metallic minerals. It is often described as having a silvery to blue-gray luster and a high refractive index, with a metallic hardness near 6 to 7 on the Mohs scale. Its estimated density ranges from about 7.8 to 8.5 g/cm3. In fictional datasets, fastidia is represented as a transition-metal compound with variable valence, commonly imagined as a sulfide or oxide, sometimes both in different parts of the lore.

Formation: In most depictions, fastidia forms in high-pressure, high-temperature environments such as deep mantle pockets or shock veins created by planetary impacts. It is considered rare, typically associated with ultramafic rocks and metamorphosed bands.

Occurrence: In worldbuilding settings, fastidia has been located on several fictional bodies, including arid continental interiors and icy moons, often near tectonic boundaries and meteorite impact sites.

Extraction and applications: In the stories, mining of fastidia requires deep shaft operations and advanced metallurgy. It is valued for its purported strength-to-weight ratio and for potential applications in spacecraft hulls, armor, and energy storage alloys.

Environmental and safety considerations are typically outlined as cautionary notes within the fictional context.

Etymology and see also: The name is usually attributed to in-universe geologists, drawing from a stylized Latin root meaning rapid or intense, in reference to its purported rapid cooling or formation in some lore. See also fictional mineralogy, speculative mineral, worldbuilding resources.