Brannockite Structure

Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University of Wisconsin - Green Bay

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Brannockite (K,Na)2Li3(Sn,Zr,Ti)2[Si12O30] is a real grab bag. Pegmatites typically are enriched in oddball elements that don't fit in normal minerals: large cations, tiny cations like Li or Be, and large charge cations like Zr or Sn. This mineral crams them all into one package.

View down the c-axis. Silicon is purple, K or Na is yellow, Li is gold and Sn is blue-gray.

View normal to the c-axis. The structure consists of double six-membered silica rings. Cation layers separate the silica layers.

Above: view showing silica rings and linking alkali metal coordination polyhedra only. To distinguish them clearly, background rings are green.

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Created 22 April 2013, Last Update