ksylemu

Ksylemu is a term used in speculative geology and science fiction to name a hypothetical mineral. It is not recognized by the IMA or in current mineralogical catalogs. In fictional treatments, ksylemu is described as a potassium-rich silicate associated with high-pressure metamorphism in subduction-zone rocks. Its structural motif is a layered or framework silicate, with possible variable hydration. Reported color is variable, often colorless to pale yellow or green, with a vitreous to pearly luster. Mohs hardness is typically described as 5 to 6, with distinct cleavage along {010} planes in fictional accounts, and moderate to high refractive index.

Formation: In these narratives, ksylemu forms when potassium-bearing fluids interact with silica under high pressure and temperature, stabilizing as a metastable phase in transition zones. P-T stability fields are imagined broadly, often overlapping those of common metamorphic silicates like kyanite and garnet, but with the added requirement of high potassium activity.

Geology and use: It is used as a teaching or worldbuilding tool to discuss mineral classification, phase diagrams, and geochemical cycles, highlighting how new minerals are named and validated. It serves as a prompt to explain the process of mineral discovery, petrographic analysis, and peer review.

Not real-world recognition: Because ksylemu lacks any verified samples or analytical data, it remains a fictitious construct of authors and educators. In serious mineralogy, only described and validated minerals with peer-reviewed evidence are considered. See also: speculative mineral, worldbuilding minerals.