Simptomite

Simptomite is a fictional mineral commonly referenced in speculative geology and worldbuilding. Descriptions present simptomite as a rare aluminosilicate with distinctive optical and magnetic properties, valuable in narrative contexts for clues about geological history. The term was coined to reflect its role as a diagnostic marker in imagined rock sequences and to evoke the notion of visible symptoms in a geologic record.

In most depictions, simptomite has a complex, variable composition with silicon, aluminum, magnesium, iron, and trace vanadium or titanium. Its nominal formula is given as (Fe,Mg)Al2Si2O7 with trace substitutions. The mineral is described as forming in high-temperature hydrothermal environments or during metamorphic recrystallization, often as prismatic crystals with a vitreous to sub-metallic luster. Coloration is highly variable, typically blue-green to emerald, driven by trace elements. Under ultraviolet light, simptomite commonly exhibits a bright, secondary luminescence.

Simptomite is depicted as occurring in deep crustal veins, ultramafic-magmatic interfaces, and occasionally in meteorite impact zones within fiction. Its crystals are said to grow slowly, requiring persistent fluids rich in silica and alumina.

In worldbuilding, simptomite serves as a speculative mineral used to illustrate geologic histories, resource distribution, or advanced energy applications in stories. Some authors assign to simptomite properties such as piezoelectric response or energy storage potential, but these are fictional extrapolations and vary between works.