meretoidust

Meretoidust is a fictional particulate material described in speculative science and science fiction. It is typically portrayed as a fine, micron-scale dust with distinctive optical and thermal behavior, used in worldbuilding to explore questions about nanomaterials, planetary regolith processes, and advanced energy concepts. The term is a coinage and does not refer to a known substance in real-world science.

In most depictions, meretoidust consists of a heterogeneous composite: a glassy silicate-like matrix interspersed with trace metallic inclusions and organic residues. Particles range from tens of nanometers to several micrometers and form fractal aggregates that scatter light with a high refractive index. The material is often described as thermally responsive, undergoing reversible phase changes under irradiation or electric fields, and as having low density yet high surface area when porous.

Within fictional settings, meretoidust can arise from specialized manufacturing processes such as microgravity vapor deposition, or as byproducts of planetary formation, asteroid processing, or alien geologic activity. It is sometimes associated with regolith-like environments on airless bodies, where dust tends to coalesce into structured halos under irradiation.

Storywise, meretoidust serves as a stand-in for advanced functional materials. Reported applications include decorative pigments with color-shifting properties, photonically engineered materials for light management, and hypothetical energy storage media leveraging high surface area. Real-world concerns in fiction mirror environmental toxicity, aggregation behavior, and stability under cosmic radiation.

See also: nanomaterials, dust, metamaterials, photonic materials. Real-world science currently does not recognize meretoidust as a known material.