Meridiaanit

Meridiaanit is the name given to a proposed mineral phase that appears in a small subset of theoretical and teaching materials within mineralogy. It is not currently recognized as a valid mineral species by major databases or by the International Mineralogical Association (IMA) and has not been independently verified in peer‑reviewed studies. The term is often used in educational contexts to illustrate issues related to mineral identification and the interpretation of powder X-ray diffraction data.

The name is derived from the fictional Meridia region in some teaching datasets, where it serves as a placeholder to discuss aluminous silicate chemistries and hydrated frameworks. In speculative models, meridiaanit is described as a hydrated aluminosilicate with a layered or framework structure, sometimes assigned to a monoclinic crystal system in hypothetical refinements.

Reported properties in non‑peer‑reviewed materials describe meridiaanit as colorless to pale green, with a vitreous to pearly luster, a Mohs hardness around 5.5–6, and refractive indices near 1.65–1.75. The proposed empirical formulas vary (for example Al2Si5O13(OH)2 or related compositions) and lack consensus.

Occurrence is described only in a single, non‑verified locality in illustrative datasets, with no corroborated mineralogical work. As a result, meridiaanit has no established industrial application and is largely of interest as a case study in mineral identification and the limitations of non‑confirmatory data.

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