Iskuille

Iskuille is a fictional mineral that appears in speculative fiction and world-building literature. It is described as a translucent crystal with color-shifting iridescence, typically showing blue to violet hues when viewed from different angles. In many settings, iskuille is valued for its clarity and light-handling properties, making it suitable for jewelry, inlay work, and decorative objects, as well as for theoretical optical applications within the story's technology.

Origin and formation: In the lore, iskuille forms in deep hydrothermal veins where silica-rich fluids crystallize under high temperature and pressure. Crystals are typically prismatic, reaching several centimeters in length, with a vitreous luster and pronounced, albeit gentle, pleochroism.

Physical properties: Iskuille is described as hard enough to resist everyday wear (roughly Mohs 6–7) and has a refractive index around 1.60–1.65. Its color shifts are influenced by trace impurities and crystallographic orientation. Clear, transparent specimens are rare; most material shows some translucence with internal lattice growth lines.

Distribution and naming: The fictional Iskuil Belt and adjacent ranges are cited as primary sources in the literature. The name iskuille is said to derive from the local language term for light and shard.

Uses and cultural significance: Within the imagined world, iskuille premium pieces symbolize status and are used in ceremonial regalia. Some cultures associate it with lunar cycles and water symbolism. Sustainable mining practices and fictional trade laws govern its extraction and sale.