-bearing veins are generally separated from topaz
-bearing veins. Pegmatite veins occur in gneisses of the Murzinka suite, and sometimes in dikes of fine-grained granites. Most veins are steeply dipping, and some have conjugate tabular bodies. The veins have been traced along strike for 50 to 400 m with widths of 2 to 10 m. Their mineral composition is essentially biotite-quartz-microcline with subordinate primary oligoclase.
Ref: E.Ya. Kievlenko, Geology of gems, 2003, p. 108
Gem list contains entries from all listed localities in region.
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