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
Schlangenberg Nature Reserve the interest in the ore which was mostly used for weapons and vessels. The greatest interest in calamine had been in the 18th century when brass manufactures settled in Stolberg (Rhineland). For the production of the alloy they needed large amounts of calamine which was melted together with copper. Before 1800 digging small reaching only surface based ore was the only technique available to the miners. In the 19th century mining changed and more than 20 adits enabled the workers to reach calamine up to 105 m below the surface. During this time the Schlangenberg-area was perforated like a Swiss