meridianit

Meridianit is a hypothetical mineral name used in geoscience discussions and speculative literature to illustrate mineral nomenclature and classification. The term is not recognized as a valid mineral by major mineralogical bodies, and there are no peer-reviewed measurements of its properties. Its etymology is typically traced to meridional or longitudinal cues in its proposed occurrence.

In fictional treatments, meridianit is described as a complex silicate or silicate-oxide mineral with a layered or framework crystal structure. Authors may describe a generic formula such as MSiO4 or a more complex silicate-oxide composition, with metal cations like Mg, Fe, or Ca. The crystal system is variably depicted as monoclinic or orthorhombic.

As a hypothetical mineral, meridianit is said to form under high-temperature and high-pressure metamorphic conditions in subduction zones or at crustal shear zones, often in association with serpentinized or carbonate-rich rocks. Its proposed occurrence along fault networks is used in fiction and pedagogy to illustrate mineral-fluid interactions and long-distance transport of elements.

If meridianit existed, it would be placed among silicate or oxide minerals depending on the favored model. Reported properties in fictional sources include a vitreous to resinous luster, a pale color range, and a moderate hardness. Because it is not observed in nature, these properties are not standardized and vary by author.

Meridianit is primarily of interest as a pedagogical or storytelling device in discussions of mineral classification, nomenclature, and the ways new minerals are described and named.