Amphibole Supergroup Minerals of Lovozero Alkaline Massif (Kola Peninsula, Russia)

On the basis of published data and results of original investigations, 21 mineral species were identified of the amphibole supergroup minerals in the Lovozero alkaline massif (Kola Peninsula, Russia). Among them, 11 species belong to sodium amphiboles, four species are sodium–calcium amphiboles, and six species are calcium amphiboles. Sodium amphiboles are widespread in alkaline rocks of all complexes in the Lovozero massif (Layered, Eudialyte, and Poikilitic), in pegmatites and hydrothermal veins, as well as in roof xenoliths of volcanoclastic rocks of the trap formation. Magnesio-arfvedsonite is the most widespread sodium amphibole, being often the rock-forming and the main melanocratic mineral. Sodium–calcium amphiboles are found in the Poikilitic complex and in xenoliths of volcanoclastic rocks. Calcium amphiboles occur only in xenoliths of volcanoclastic rocks altered metamorphically or metasomatically in varying degree. The morphology, chemical composition, isomorphic substitutions, and paragenesis of amphiboles in the Lovozero massif are considered, as well as their belonging to different varieties and complexes of rocks and their abundance. A critical review of previously published data on amphiboles from rocks of the Lovozero massif is given according to the present nomenclature of the amphibole supergroup minerals.