Esitluskihil

Esitluskihil is a fictional mineral species widely used in geology education and worldbuilding. In the fiction, it is described as a layered silicate mineral that combines alternating sheets of silicon-oxygen tetrahedra with metal-oxide layers, yielding an anisotropic crystal with distinct optical and physical properties.

Etymology: The name derives from the fictitious Esitlusk region and the common mineral-name suffix -hil, used in the setting to denote minerals with layered structures.

Occurrence and morphology: Esitluskihil crystals are typically prismatic to tabular, up to about 2 cm, with a color range from colorless to pale yellow. It has a vitreous to pearly luster and is transparent to translucent. Mohs hardness is about 6; cleavage is good along {010}; refractive indices are near nα=1.66, nβ=1.70, nγ=1.72; specific gravity around 3.2.

Formation and associations: In the fictional geology, Esitluskihil forms during high-temperature metamorphism in granulite facies rocks, in the presence of low-salinity fluids. It often occurs with cordierite, sillimanite, quartz, and magnetite.

Uses and significance: In teaching, Esitluskihil serves as an example of layered silicate structures and the relationship between crystal geometry and anisotropy. It also appears in science fiction as a plot device highlighting metamorphic processes and mineral resources.

Notes: Esitluskihil is not a real mineral and is not listed by the International Mineralogical Association. The article content reflects fictional usage within educational and literary contexts.