Kiellon

Kiellon is a fictional mineral described in speculative geology and science fiction. It is valued in narratives for its vivid blue crystals and unusual stability under heat.

The name kiellon is taken from a fictional Kiellon River region used in several world-building texts.

In these stories kiellon forms in hydrothermal veins and pegmatites within regional metamorphic rocks, under high-temperature, moderate-pressure conditions, often replacing aluminous minerals.

Kiellon typically presents blue to indigo prismatic crystals with a vitreous luster. It has a Mohs hardness around 6 to 6.5 and a density near 3.2–3.6 g/cm3. Its composition is described as a potassium-aluminosilicate with oxygen, silicon, and trace amounts of iron, magnesium, and titanium.

In fiction kiellon is sometimes described as a semi-precious gemstone and as an energy-conductive material or high-temperature insulator; in non-fiction speculative contexts it serves as an example mineral to illustrate properties of metamorphic fluids.

It is mined by hypothetical open-pit operations and refined to produce blue crystals suitable for jewelry or laboratory analogs.

See also: fictional minerals, speculative geology.