Associated Minerals and Geochemistry of Amazonite

The mineralogical and geochemical conditions of the amazonite formation in all genetic types of the rocks are described; in particular, different amazonite generations formed in association with the rare-metal and rare earth elements (REE) mineralizations in a Precambrian pegmatite of western Keivy (Kola Peninsula, Russia). Within these pegmatites, 75 mineral species have been identified, presenting almost all the crystal-chemical classes. The most common minerals are amazonite, microcline, albite, biotite, zinnwaldite, and quartz. The accessory minerals include Ta and Nb oxides as well as REE silicates and phosphates. In these pegmatites, various stages of formation have been established (Na-metasomatism or albitization, amazonite formation, and fluorite deposition), all of which are associated with various types of rare-metal and REE mineralizations.