This study covers the northwestern area of the emerald belt in the Muzo-Coscuez District located in the western edge of the Eastern Cordillera of Colombia, Departamento de Boyaca. The study area includes sediments of Lower Cretaceous age, affected by fault systems and fractures which were accompanied by mineralizing events produced from fluid migration reacting with cromophores of the including rock, providing the esmeralds origin. The emerald mineralization is stratigraphically restricted to the shaly level of the carbonaceouscalcareous facies locked toward the top of Calcareous Shale member and base of the Carbonaceous Shale unit of Paja Formation. This shaly unit is mineralogically associated whith rhombohedral calcite, pyrite, albite and pyrophyllite, which are minerals formed at low temperature conditions, as a result of post-magmatic hydrothermal-neumatholithic processes and fluids provided by the including rock. Geochemically it is established that the albitization processes favor the emerald formation, meanwhile the potassic metasomatism related to regional metamorphism and dynamic tectonism inhibit the emerald mineralization as high temperatures are generated. The best indicators at local and regional considerations to conduct the geochemical exploration for emeralds are the behavior of chemical elements present in the water, active sediments, soil and rocks where the anomalous concentration of Na/K are higher than 1.The high anomalous concentrations of sodium and some elements in rare earths constitute also excellent indicators to conduit geochemical exploration.