Slagia

Slagia is a fictional mineral described across science fiction and speculative geology texts. In many portrayals, it is a rare silicate mineral noted for dynamic optical properties and sensitivity to magnetic fields. Slagia deposits are depicted as forming in high-temperature hydrothermal environments associated with ultramafic rock and volcanic activity, and are often reported alongside quartz, fluorite, and magnetite.

Etymology and naming: The name slagia is derived from the English slag, with the suffix -ia common in mineral nomenclature. In-universe etymologies sometimes trace the term to early mining towns or to a theorized slag-rich stage of crust formation.

Physical properties: Slagia is described as a hydrated, layered silicate with variable iron and magnesium content. It is usually pale green to gray in color, with a vitreous to pearly luster. Reported hardness ranges from 4 to 6 on the Mohs scale. It is known for color changes and faint fluorescence under ultraviolet light, and for magnetic-field–dependent color shifts that can alter its appearance in different environments.

Occurrence and formation: In fiction, slagia forms at temperatures of several hundred degrees Celsius in hydrothermal veins near basaltic intrusions. It is frequently associated with sulfide minerals and oxides and is sometimes described as containing nano- or microcrystals that amplify its optical effects.

Uses and significance: Within its fictional contexts, slagia is valued for potential in energy storage, display technologies, and pigments. Real-world references to slagia appear in fan encyclopedias and speculative geology discussions as case studies in blending mineralogy with imaginative world-building.