amphibole: Quick Facts

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Diagram comparing two mineral structures: the top shows a single chain of silicon-oxygen tetrahedra for pyroxene labeled (SiO3)n, while the bottom shows a double chain for amphibole labeled (Si4O11)n, with silicon atoms in purple and oxygen atoms in orange.

Figure 3: Projection of the crystal structure of a monoclinic amphibole as viewed down the a axis.

Figure 4: (A) Schematic projection of the monoclinic amphibole structure on a plane perpendicular to the c axis. (B) Control of cleavage angles by I beams in the amphibole structure.

Riebeckite (of the crocidolite variety) from South Africa.

Bowen's reaction series

Diagram illustrating the structural linkage types among silicate minerals, showing geometric arrangements of silicate tetrahedra for nesosilicates, sorosilicates, cyclosilicates, inosilicates (single and double chain), phyllosilicates, and tectosilicates, each with example minerals and unit compositions labeled.

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Topics

sodic amphibole group tremolite-actinolite series calcic amphibole group sodic-calcic amphibole group iron-magnesium-manganese amphibole group nephrite hornblende actinolite edenite pargasite pyroxene

Basalt sample returned by Apollo 15, from near a long sinous lunar valley called Hadley Rille. Measured at 3.3 years old.

(Bed) Rocks and (Flint) Stones