amphibole mineral, an iron-rich sodium silicate. Lithium and magnesium replace iron in the structure to form eckermannite. Both minerals characteristically occur as dark-green crystals in alkali igneous rocks and their associated pegmatites. For chemical formula and detailed physical properties, see amphibole (table).
Meaning of ARFVEDSONITE in English
Britannica English vocabulary. Английский словарь Британика. 2012