Amfibolisen

Amfibolisen is a mineral species described within the amphibole group. It is a magnesium–iron silicate with aluminum and calcium as common substituents and is typically found in hydrated metamorphic rocks. Amfibolisen crystals are usually elongated and prismatic, with a vitreous luster. In hand specimen and thin section, it shows the characteristic amphibole cleavage near 56° and 124°, and a Mohs hardness around 5–6. It forms under medium to high-grade metamorphic conditions and is often associated with other amphiboles and pyroxenes.

Chemically, amfibolisen exhibits a solid-solution system that includes magnesium, iron, aluminum, calcium, and sometimes sodium. The mineral belongs to the double-chain silicate framework of amphiboles and commonly contains hydroxyl groups, with trace fluorine or chlorine in some samples. Its exact composition varies with metamorphic history and precursor rock chemistry.

Occurrence and formation: Amfibolisen is reported from ultramafic and metamorphic rocks such as serpentinites, granulites, and migmatites, where fluids and elevated temperatures promote amphibole crystallization. It can serve as a petrological indicator of metamorphic conditions and rock provenance.

Etymology and status: The name Amfibolisen derives from the amphibole tradition and is used in some educational or illustrative contexts as a hypothetical or prototypical amphibole species rather than a widely recognized mineral.

Analytical interest: Identification relies on optical microscopy, X-ray diffraction, and electron probe microanalysis to determine crystal structure and composition. Amfibolisen is primarily of interest for scholarly and educational purposes in petrology rather than commercial use.

See also: Amphibole, Silicate minerals, Metamorphic rock.