From what geological formation are Brazilian emeralds primarily mined?

Brazilian emeralds are primarily mined from pegmatites, particularly where these formations intersect with schists. Pegmatites are coarse-grained igneous rocks that can contain a variety of minerals, including beryl, the mineral from which emeralds are derived. The unique conditions present in pegmatitic environments, such as the presence of water during crystallization, contribute to the formation of high-quality emeralds with rich color and transparency. Additionally, the proximity to schists, which are metamorphic rocks, can enhance the conditions necessary for the growth of the beryl crystals, thus making this geological formation particularly significant for Brazilian emerald production. The formation of these stones within such an environment is crucial to understanding their occurrence and the characteristics that make them highly sought after in the gemstone market.