greiiau
Greiiau is a fictional mineral described in speculative fiction and worldbuilding contexts. In these settings, greiiau is presented as a rare blue‑green hydrothermal silicate mineral with metallic trace elements that produce a distinctive glow under ultraviolet light. Crystals are typically prismatic to tabular, with a vitreous to glassy luster. The Mohs hardness is usually placed in the 5–6 range, making it workable with conventional tools within the narrative, though it remains scarce in practical mining.
Formation and distribution are described as taking place at subduction zones where mineral-rich fluids alter silica-bearing
Uses and significance vary by work but commonly include energy storage and luminescent effects. In-world myths,
History and etymology are also part of its lore. The term greiiau is attributed to a mythic