Tsaramanga pegmatite, Mahaiza, Betafo, Vakinankaratra, Madagascar

Pegmatite vein containing gem minerals near Tonga Mountain, 15 km south of the town Betafo. An intensely kaolinized pegmatite cuts granitic-gneisses near their contact with amphibolized gabbroids. Large transparent crystals of blue beryl are found, some of which have yellow or green tints or dark green cores. Spectacular druses of smoky quartz and aquamarine with brilliant faces are found within accumulations of red (pocket) clay. Black tourmaline (schorl)is common. Garnets (almandine-spessartine series), columbite, betafite, metamict zircon, magnetite, molybdenite (as inclusions in quartz), and other minerals are present.

Ref: E.Ya. Kievlenko, Geology of gems, 2003, p. 112

Gemstone List

Copyright © Jolyon & Katya Ralph 1993-2021. Site Map. Locality, gem & photograph data are the copyright of the individuals who submitted them. For more information please contact the . Gemdat.org is an online information resource dedicated to providing free gemmological information to all.