Kakskihiline

Kakskihiline is a fictional mineral used in speculative geology and in works of fiction to illustrate mineralogical concepts. In the imagined taxonomy, it is a rare alkali aluminosilicate that forms in high-temperature metamorphic belts. The name derives from the Kakshi region in the fictional Kakshian geology, with the suffix -iline common to mineral names in that setting.

In terms of properties, kakskihiline is described as crystallizing in the monoclinic system and forming tabular prismatic crystals that can reach several centimeters. It is typically depicted as a pale blue to emerald-green mineral with a vitreous to pearly luster and a white streak. Reported hardness is around 6 on the Mohs scale, and the specific gravity is placed roughly between 3.1 and 3.4.

Occurrence and formation: In the fictional account, kakskihiline forms in metamorphosed ultramafic rocks and alpine-type contact zones where fluids promote metasomatic alteration. Formation temperatures are placed approximately 500–700°C and pressures at a few kilobars. It is often described as occurring with quartz, mica, and nepheline.

Uses and significance: Within its fictional universe, kakskihiline is valued as a decorative gemstone and is occasionally proposed for specialized ceramic or refractory applications due to presumed stability at elevated temperatures. It has no verified occurrences in the real world and is not recognized by geological authorities.

History: First described in-universe in speculative mineral catalogs and fiction from the late 20th to early 21st century, with several authors expanding its properties.

See also: List of fictional minerals; Kakshi region; Silicate minerals in fiction.

References: Fictional encyclopedia entries and in-universe catalogs.