llyggj

Llyggj is a fictional mineral described in speculative fiction and worldbuilding, particularly in the Brannor setting. It is described as a dense silicate-oxide mineral with a natural blue-green phosphorescence that increases with exposure to light after extended darkness. It forms in high-temperature magmatic intrusions and is commonly found in tabular crystals within hydrothermal veins. Physical properties include a Mohs hardness of about 6.5 to 7 and a high dielectric constant, making it useful in energy storage and electrical insulating applications in the fiction.

In-universe etymology: The name llyggj is from a constructed Brannori language; some scholars interpret it as a compound of elements meaning light and ridge, though interpretations vary by culture.

Occurrence and mining: In most narratives, llyggj deposits occur in remote mountainous regions of Brannor; mining is capital-intensive due to deep veins and the mineral's brittle cleavage. Extraction is typically followed by careful heat treatment and diffusion dosing to unlock luminescence.

Uses and significance: Because of its luminescence and energy properties, llyggj features in fictional power systems, compact energy cells, and optical components. It also appears in jewelry and ceremonial ornamentation, valued for a steady glow.

Cultural context: In Brannor folklore, llyggj is associated with guiding lights and memory; scholars discuss its symbolic role in thresholds and decision-making.