Copper is a chemical element with the symbol Cu (from cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; a freshly exposed surface has a reddish-orange color. It is used as a conductor of heat and electricity, a building material, and a constituent of various metal .
Mississippian copper plates, or plaques, are plain and repousséd plates of beaten copper crafted by peoples of the various regional expressions of the Mississippian culture between 800 to 1600 CE. They have been found as artifacts in in the American Midwest and Southeast. The plates, found as far afield as Florida, Georgia, Illinois, Mississippi, Oklahoma, Tennessee, and Wisconsin, were instrumental in the development of the archaeological concept known as the Southeastern Ceremonial Complex. Some of the..
Zinc, in commerce also spelter, is a chemical element; it has the symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is 2. Zinc is the 24th most abundant element in the Earth's crust and has five stable . The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest mineable amounts are found in Australia, A..
