Inguniaals

Inguniaals are a fictional class of minerals described in speculative geology and in a popular science fiction setting. They are characterized by a layered, plate-like crystal habit and a distinctive iridescent transparency that changes with light. In the imagined geology, inguniaals consist of a hydrated aluminosilicate carbonate group, and they form in high-pressure, low-temperature hydrothermal veins within subduction-zone rocks.

In terms of structure, inguniaals are described as possessing a quasi-hexagonal lattice with alternating layers of silicate sheets and carbonate-rich layers, giving them unique cleavage and refractive properties. Hydration levels can vary, which in turn influences color and stability. They are often associated with minerals such as epidote, chlorite, and quartz in the fictional vein assemblages.

The concept originated in the world-building literature of the Xenar Chronicles, where inguniaals were first defined by geologist Dr. Mira Kalen in 2149. The name is said to derive from a root meaning edge or boundary in the in-universe language, reflecting their proposed formation at the edge of metamorphic microenvironments.

In-universe significance: inguniaals are used as a diagnostic indicator of specific metamorphic histories and are occasionally depicted as ornamental stones in media. In real-world geology, there is no recognized mineral class by this name.

See also: fictional minerals; hydrothermal mineralogy; metamorphic rocks.