Omaksumia

Omaksumia is a hypothetical inorganic mineral proposed in theoretical high‑pressure mineral physics. The name is drawn from a fictional mantle region used in modeling, and the term is used in speculative discussions about mineral phases that could exist under ultrahigh pressures.

The concept of omaksumia arose from computational predictions that a silicate phase with a layered framework might become stable at pressures found deep in subduction zones or the Earth’s mantle transition zone. As a theoretical mineral, it has not been observed in nature and has not been produced as a durable, ambient‑condition sample in experiments. Predictive models describe a crystallography consistent with a hexagonal or closely related symmetry, and a composition dominated by silicon and oxygen with magnesium and aluminum as major cation components, with possible trace iron or calcium.

Proposed properties are provisional and depend on the assumed pressure–temperature path. In the models, omaksumia would be relatively dense for a silicate, have a hardness comparable to other mid‑range silicates, and exhibit a coordination environment that changes with pressure. Its appearance in small synthetic crystals is described as colorless to pale gray; larger specimens, if stabilized, might show translucency under suitable conditions.

Occurrence and stability are central to the concept: omaksumia is expected to form only under extreme pressures and temperatures, such as those encountered in subducted lithosphere or during mantle‑scale processes, and would likely be unstable at surface conditions, reverting to known silicate phases.

Current status remains theoretical. No verified natural sample or durable synthetic analogue has been confirmed, making omaksumia a topic of interest for models of deep Earth mineralogy rather than an established mineral. See also high‑pressure minerals, silicate minerals, and perovskite‑related phases.