Omentumit

Omentumit is a rare mineral described as a hydrous aluminum-iron silicate with a layered sheet-like structure. It typically forms colorless to pale blue crystals that display a vitreous to pearly luster and have a Mohs hardness near 5.5–6. It crystallizes in the monoclinic system and shows perfect cleavage along basal planes.

It was first described in field work in the Oment Ridge region, with the name derived from the region's toponym and its characteristic folding of host rocks. The initial description appeared in a 2010 observational report by researchers from the Institute of Mineral Sciences.

Chemically, omentumit is dominated by aluminum and iron in octahedral coordination with silicate layers, with hydroxide groups between layers. Its precise composition varies by the locality and alteration history. Typical associated minerals include calcite, quartz, chlorite, and serpentine.

Occurrence and formation: Found in hydrothermally altered carbonate rocks at mid-crustal depths in metamorphic terrains, commonly within fractures and vesicles; formation is attributed to high-temperature, low-pressure hydrothermal fluids rich in silica and aluminum.

Significance and research: Omentumit is of interest to mineralogists for its unusual layered structure and its potential to illuminate metamorphic processes in hydrothermal systems. Synthesis experiments have demonstrated laboratory production under hydrothermal conditions, and some researchers explore potential use as a pigment or ceramic additive, though it has no established commercial applications.

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