feathersis

Feathersis is a fictional mineral noted for its plumose, feather-like crystal habit and its subtle iridescence. It crystallizes as slender, acicular fibers that radiate from a central axis, creating a feathered appearance. Descriptions of its chemistry portray a silicate-rich phase with variable iron and magnesium content; exact compositions are said to vary by deposit. On the Mohs scale, feathersis is placed around 6.5 to 7, and it has a specific gravity near 4.0. The mineral is typically translucent and shows pastel coloration, with weak pleochroism that shifts with the observer’s angle.

Formation and occurrence: In the fictional geologic setting, feathersis forms in volatile-rich hydrothermal systems within ultramafic rocks. Fibrous growth is promoted by fluids containing light halogens, resulting in fine needle-like crystals that assemble into plumes. Natural occurrences are described as occurring in narrow veins and as inclusions in coarser minerals; some accounts place deposits in pegmatitic pockets.

Discovery and etymology: The name feathersis derives from Latin penna, meaning feather, combined with the suffix -sis used in mineral nomenclature to indicate a process or state. It was first described in 2147 by researchers in the Zephyrian field guides, and has since featured in speculative geology and world-building references.

Uses and cultural context: In fiction, feathersis is valued for its delicate sheen and is used in jewelry and decorative pigments. Its fibrous texture has drawn interest for potential optical applications in fictional technologies and art. Because feathersis is a fictional mineral, real-world reports treat it as a speculative concept rather than a studied mineral species.