Minerals of the Österby pegmatite, Dalarna, Sweden

Abstract

The Österby pegmatite is a granite pegmatito which has been worked intermittently for feldspar and quartz. The occurrence of rare-earth minerals was first recorded in 1884 and the mineral thalenite, Y₂Si₂O₇, was originally described from this locality in 1898. The following minerals have been identified from the pegmatite: quartz, albite, muscovite, fluocerite, thalenite, allanite, gadolinite, samarskite, yttrotantalite, xenotime, fluorite, and asphaltite.