portfellide

Portfellide is a fictional mineral introduced for educational and speculative purposes. It is not recognized in real-world mineral catalogs, and its properties vary across sources. The name combines the imagined Portfell region with the common mineral suffix -ide, following standard naming conventions.

In the fictional accounts, portfellide is described as a silicate mineral with a vitreous to resinous luster. Color ranges from pale green to deep blue, and it is assigned a Mohs hardness around 6 to 6.5. Reported specific gravity values are in the mid-range for silicates, and refractive indices are typically given as roughly 1.72 to 1.78. Descriptions of cleavage are variable in fiction, with some sources noting imperfect or limited cleavage and others describing it as having a conchoidal fracture in places. The mineral is often said to belong to metamorphic settings.

Formation in fictional narratives is usually tied to high-temperature metasomatic processes in ultramafic or high-grade metamorphic rocks, with temperatures on the order of several hundred degrees Celsius. Crystals are depicted as euhedral and small, commonly occurring with minerals such as olivine, magnetite, and chromian spinel.

Occurrence in stories is likewise fictional, typically confined to imagined ranges or districts where metamorphic rocks predominate. In teaching contexts, portfellide serves as a placeholder example to illustrate mineral properties, nomenclature, and how minerals are described in field notes and reports. There are no verified specimens or real-world references to portfellide.