South America : Colombia : the western and eastern zones of the Eastern Cordillera : still number 1 in the world Emerald : the most valuable beryl : the most precious gemstone Schwarz, D. /Giuliani, Gaston PETROGRAPHIE MINERAL BERYLIUM MINE REPARTITION GEOGRAPHIQUE HISTOIRE ECONOMIQUE GITOLOGIE Lapis International /Giuliani, Gaston (ed.) Jarnot, M. (ed.) Neumeier, G. (ed.) Ottaway, T. (ed.) Sinkankas, J. (ed.) Staebler, G. (ed.) 2002 text https://www.documentation.ird.fr/hor/fdi:010030128 fdi:010030128 Schwarz D., Giuliani Gaston, . South America : Colombia : the western and eastern zones of the Eastern Cordillera : still number 1 in the world. In : Giuliani Gaston (ed.), Jarnot M. (ed.), Neumeier G. (ed.), Ottaway T. (ed.), Sinkankas J. (ed.), Staebler G. (ed.), . Emerald : the most valuable beryl : the most precious gemstone Lapis International, ; 2). 2002, 36-45 EN COLOMBIE