Rúnnab

Rúnnab is a fictional mineral described in contemporary fantasy and speculative geography. Valued for its soft glow and exceptional stability, it is commonly depicted as harvesting resource in mountainous mining belts. The name rúnnab appears in a constructed language used in multiple in-world cultures; etymology combines elements meaning rune or inscription with gleam, reflecting its characteristic luminescence.

In most accounts, rúnnab crystals are prismatic, typically pale blue to violet, with a steady internal glow visible in low light. It is described as a silicate-aluminate mineral with trace lanthanides. Reported hardness ranges from 6.5 to 7 on the Mohs scale, and it takes a high polish.

Rúnnab is said to form during regional metamorphism in mountainous belts, crystallizing in fissures within schist and gneiss. In-world radiometric dating places its original formation at hundreds of millions of years ago. Modern deposits are localized and mined from discrete seams; extraction is labor-intensive due to its brittle crystal habit.

Its primary value lies in photonic applications. Refined rúnnab powders are used in lasers, optical fibers, and high-density data storage components. In some settings, the mineral is cut into singulated facets for rune-inscribed artifacts, where it is believed to stabilize inscriptions and extend their readability. It is also used as a pigment in specialized varnishes and glass.

Rúnnab is treated as a strategic resource in fictional economies, with price and supply tied to mining output and regulatory controls. Academic and literary works note its symbolic role as a scarce energy- or information-bearing mineral in world-building contexts.