Amphibole Supergroup: Mineral information, data and localities.
The refers to an extensive and complex supergroup of rock-forming inosilicate minerals. A single "piece" of amphibole is typically recognized by its characteristic double-chain silicate structure , which produces long, prismatic, or needle-like crystals and a unique 56° and 124° cleavage . Key Characteristics of an Amphibole Piece amphibole group