Beryl-muscovite pegmatites within quartzites and sillimanite schists of the middle Proterozoic Umkondo system in the Zambezi Rhodesian massif metamorphic belt. Their absolute age is 480 to 680 Ma.
Gem-quality greenish blue, pale blue, golden, yellow, and colourless
beryl was recovered from weathered zone, which considerably enhanced mining.
Transparent material free of inclusions and fractures is trimmed from larger feculent crystals. Light yellow
beryl dominates in the upper parts of the pegmatite body, greenish and blue
aquamarine are more abundant at depth. RI for yellow
beryl is 1.574-1.580, density is 2.721 g/cm³, RI for
aquamarine is 1.578-1.584 and density is 2.725g/cm³.
Ref: E.Ya. Kievlenko, Geology of gems, 2003, p. 114Gemstone List
Gem list contains entries from all listed localities in region.
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