The M1, M2, and M3 sites of these minerals are occupied by magnesium and iron 2+ ions, and monoclinic varieties of these minerals are in the space group C2/m.
Unlike a similar group, these very rarely exhibit exsolution lamellae. The OH rule for these minerals requires the addition of a hydrogen atom to balance the charge of apical oxygen atoms. The M1, M2, and M3 sites of these minerals are occupied by magnesium and iron 2+ ions, and monoclinic varieties of these minerals are in the space group C2/m. Sodic examples of these minerals include Riebeckite and Arfvedsonit, while non-sodic members include anthophyllite and actinolites. These minerals are found below pyroxenes on the Bowen's reaction series, and their structure usually features two single chains, which joint at a corner atom, giving them a 4:11 ratio of silicon to oxygen. For 10 points, identify this class of minerals, which contains tetrahedral chains of SiO4 and includes hornblendes.
Unlike a similar group, these very rarely exhibit exsolution lamellae.
amphiboles