Robuta

https://www.gia.edu/gems-gemology/spring-2022-gem-topaz-schneckenstein-crag-saxony-germany-mineralogical-characterization-luminescence Gem Topaz from the Schneckenstein Crag, Saxony, Germany: Mineralogical Characterization and... Characterizes yellow topaz from this historical source, with particular emphasis on its photoluminescence behavior. from thesaxony germanygemtopazschneckenstein