Calamine brass a mixture of the virtually indistinguishable zinc ores smithsonite and hemimorphite) as the zinc component of brass. The resulting brasses, produced by heating a mixture of copper and calamine to a high temperature for several hours (allowing zinc vapor to distill from the ores and permeate the metallic copper), contained a significant amount of slag material resulting from the non-zinc components of calamine. The use of ore rather than metallic zinc also made it difficult to accurately produce the desired final proportion of copper to zinc. This process is known as cementation. Calamine brass was produced using proportions of two-sevenths
Group 3 element be reduced to their elements, meaning that the discovery of a new earth was equivalent to the discovery of the element within, which in this case would have been "yttrium". Until the early 1920s, the chemical symbol "Yt" was used for the element, after which "Y" came into common use. Yttrium metal was first isolated in 1828 when Friedrich Wöhler heated anhydrous yttrium(III) chloride with potassium to form metallic yttrium and potassium chloride. In 1869, Russian chemist Dmitri Mendeleev published his periodic table, which had empty spaces for elements directly above and under yttrium. Mendeleev made several predictions on the