OHsidos

OHsidos is a fictional mineral described in speculative geology and collaborative worldbuilding projects. It is depicted as a hydrous oxide with a layered crystal structure and a distinctive pale blue-green hue.

Etymology and naming: The name OHsidos combines hints of hydroxide chemistry with a suffix alluding to layering in its crystal habit; the term is used within the fiction to indicate a compound that forms through hydrothermal alteration.

Properties: In the fictional profile, OHsidos has a Mohs hardness around 5, a vitreous to pearly luster, and a color range from pale blue to teal. Crystals are typically slender prismatic forms, often displaying weak birefringence under polarized light and faint blue fluorescence under ultraviolet illumination. It is described as moderately reactive with strong oxidizers at elevated temperatures.

Occurrence: OHsidos is said to form in hydrothermal veins hosted by basaltic or ultramafic rocks, typically in subduction-related settings or in volcanic arcs. It commonly occurs with magnetite, serpentine, calcite, and quartz.

Synthesis and use: In the fictional setting, OHsidos can be synthesized in high-temperature, high-pressure hydrothermal reactors and recovered as a decorative gemstone or as a functional material. The speculative applications include ion-exchange catalysis, battery electrolytes, and lightweight structural composites.

Cultural context: OHsidos has appeared in science fiction literature and role-playing worlds as a mineral of interest for exploration and trade. In-universe discussions emphasize its rarity and its aesthetic appeal.