Felsigranitoidisissa

Felsigranitoidisissa is a hypothetical silicate mineral species described in geologic fiction and in didactic discussions of granitoid petrogenesis. The name combines felsic affinity (fels) with granitoid character and the suffix -idisissa, modeled on mineral-naming conventions.

Composition and structure: It is envisaged as a feldspathic silicate with a framework similar to alkali feldspars, enriched by quartz intergrowths and occasional mica lamellae. In this concept, felsigranitoidisissa displays a characteristic lamellar exsolution fabric and a solid-solution relationship with microcline and albite, with trace Fe-Ti-rich phases.

Occurrence and formation: In the fictional felsigranito belt, felsigranitoidisissa is proposed to form during high-temperature metamorphism and metasomatism of granitic rocks, typically under subduction-related conditions that promote partial melting and re-crystallization.

Physical properties: In this portrayal, the mineral would show a vitreous to pearly luster, color ranging from pale pink to gray, Mohs hardness around 6.5, and two good cleavages approximately at 90 degrees. Crystals are described as tabular to prismatic, commonly forming aggregates with quartz and mica.

Classification and status: Felsigranitoidisissa is not recognized by the International Mineralogical Association and is described here as a hypothetical example used to illustrate granitoid petrogenesis and mineral identification techniques.

Analytical methods and significance: Identification in this concept relies on X-ray diffraction, electron microprobe analysis, and Raman spectroscopy. The mineral serves in teaching about mineral solid solutions, textures, and isotopic dating within granitoid systems.