gems, Brazil, topaz, imperial topaz, Capão, Minas Gerais, euclase

Kenngott discusses specimens of euclase, topaz, diamond, and pyrrhotite from Brazil, describing their mineralogical and crystallographic characteristics. He records observations on crystal form, physical properties, and associations, with particular attention to features useful in characterizing the Brazilian specimens. The paper contributes to nineteenth-century knowledge of Brazil’s rich mineral resources and is of gemological interest for its treatment of three important Brazilian gem minerals—euclase, topaz, and diamond.