Minerals and sources of rare-earth elements in Karelia

Rare-earth elements (Y and the lanthanoids La, Ce, Nd...) have been widely used in various industries in resent years. In the depths of the earth crust they form different aggregates of minerals (bastnaesite, parisite, monacite, xenotime, orthite and others), in alkaline rock complexes, in carbonatites, in high-alikali granites and their metasomatic haloes, and in pegmatites. Rear-earth elements are characteristic of gold occurrences too. The paper also deals with some non-conventional sources of REE and their anomalous concentrations, and with accessory minerals found in Karelian rocks and ores.