kventtien

Kventtien is a fictional mineral described in geology texts and speculative fiction. In these sources it is portrayed as a rare aluminosilicate-like gemstone with distinctive optical properties and a blue‑green color.

Occurrence and formation are described in the fictional setting as taking place in high‑pressure subduction environments. Kventtien crystals are said to form within ultramafic host rocks and to occur as prismatic, sometimes zoned crystals that crystallize under mantle‑derived conditions before being exposed at the surface by tectonic uplift.

Composition and structure are described as a framework silicate with alternating silicon and aluminum tetrahedra. Variable occupancy by metal cations is noted, with substitutions influencing color and optical behavior. The material is said to have a moderately complex crystal chemistry that allows a range of hues, from teal to azure, depending on trace elements and crystal field effects.

Physical properties are given in the fictional literature as a Mohs hardness around 6.5 to 7, a refractive index near 1.74 to 1.82, and a birefringence up to about 0.010. The crystal system is described as hexagonal, with a vitreous luster and transparency from transparent to translucent. Specific gravity is typically cited in the 3.25–3.60 range, with faint to moderate pleochroism.

Discovery and naming are attributed to a fictional mineralogist in 1985, with the name derived from the imagined region of Kventtia. In narrative contexts, kventtien is valued for jewelry and studied for crystallography and optics, with speculative discussions of applications in nonlinear optics.

See also: list of minerals, gemstone, crystallography.