The Lake Manyara deposit is on the western shore of Lake Manyara, 35 km NE of Mbulu settlement.
Emerald and
alexandrite were mined in relatively small quantities from the biotite schist at the contact with pegmatites. They occur with apatite, yellow chrysoberyl, pyrope-almandine garnet, spinel, olivine, clinopyroxene, chondrodite, corundum, phenakite, tourmaline, light-coloured beryl, and other minerals.
The
emerald crystals are characterized by inclusions of mica, apatite and quartz, as well as gas-liquid inclusions in the form of negative crystals and fan-shaped healed fractures. RI of
emerald is 1.576 - 1.590, density is 2.69 - 2.75 g/cm³.
Ref: E.Ya.Kievlenko, Geology of gems, 2003, p. 86
Gemstone List
Gem list contains entries from all listed localities in region.
Localities in this Region
|