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
Ore Mountain cuisine of potato are also common, the best-known is the so-called "Rauchemaad". At Christmas, which is especially richly celebrated in the Ore Mountains, many households still make "Neinerlaa". The ingredients vary from region to region, sometimes even from village to village. In any case, on Christmas Eve nine elements are served, for example, bratwurst, sauerkraut and lentils, each element supposedly having a special significance for the coming year. For example, dumplings stand for wealth and celery for fertility Ore Mountain cuisine Cuisine in the Ore Mountains was dominated for centuries by the changing economic circumstances of the mining, handicraft and forestry