Doloen

Doloen is a hypothetical silicate mineral used in theoretical discussions of mineralogy and high‑pressure metamorphism. It is not currently recognized by the International Mineralogical Association, and no natural specimens have been confirmed. The term doloen appears in thought experiments and teaching materials as an illustrative example of how minerals might form under extreme conditions.

Etymology and naming in these contexts often trace doloen to a fictional locality or to generic naming conventions used in mineralogy discussions. Because doloen is not an established mineral, there is no standardized naming origin or accepted set of crystallographic or chemical specifications.

In thought experiments, doloen is described as forming under ultrahigh-pressure metamorphic conditions, such as those that can occur in deep subduction zones. It is posited to arise from reactions among magnesium- and iron-rich silicates in the presence of volatile fluids, at pressures around several gigapascals and high temperatures. In such scenarios, doloen is often paired in discussions with other high‑pressure phases like garnet or coesite to illustrate phase transitions and mineral stability fields.

Physical and optical properties attributed to doloen in hypothetical contexts include a tetragonal crystal system, a hardness around 7.0–7.5 on the Mohs scale, and a vitreous luster. Color is described as colorless to pale blue, with a white streak and transparency ranging from transparent to translucent. A characteristic feature in these discussions is the suggestion of variable composition, typically described as a complex silicate-oxide with magnesium, iron, aluminum, and trace elements, rather than a fixed chemical formula.

Doloen serves as a teaching tool to explore mineral identification, nomenclature practices, and the limits of mineral discovery in high‑pressure geology. See also mineral, silicate, high-pressure metamorphism.