Fersmite

Fersmite is a fictional mineral used in speculative fiction and role-playing games. It is depicted as valuable for energy storage and luminescence, making it a sought resource in advanced technologies and magic-enabled worlds.

Physically, fersmite appears as a dense, metallic ore with a steel-gray to blue-green sheen. In many depictions it crystallizes in the isometric system, forming coarse, prismatic crystals. It is commonly described as Mohs 6–7 with a density around 5.0–5.5 g/cm3. A characteristic feature is a faint internal glow under ultraviolet light, usually a pale blue or green hue caused by trace elements.

Formation and occurrence: In fiction, fersmite forms in shock-altered rocks from meteorite impacts or in rapid-cooling igneous environments. It is mined from deep crustal veins, meteorite fragments, or specially tempered pockets in volcanic rocks.

Uses: Its purported high energy density and stability make fersmite a preferred power source for reactors, batteries, and field devices. It also serves as a catalyst in imaginative alchemical processes and as a luminescent marker for navigation and signage. Refining and handling are often shown as requiring protective atmospheres and high-temperature furnaces to prevent degradation.

Etymology and cultural references: The name blends "fer" (iron) with the common mineral suffix "-mite." The mineral appears across works of fiction and tabletop games as a rare and valuable resource.