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Slate is a fine-grained, foliated, homogeneous, metamorphic rock derived from an original shale -type sedimentary rock composed of clay or volcanic ash through low-grade, regional metamorphism. It is the finest-grained foliated metamorphic rock. [1] Foliation may not correspond to the original sedimentary layering, but instead is in planes ...
Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion . Of the large number of different types, the best known traditional types are bronze , where tin is a significant addition, and brass , using zinc instead.
Tarnishes to black or green in air. Native copper is an uncombined form of copper that occurs as a natural mineral. Copper is one of the few metallic elements to occur in native form, although it most commonly occurs in oxidized states and mixed with other elements. Native copper was an important ore of copper in historic times and was used by ...
The Old Copper complex or Old Copper culture is an archaeological culture from the Archaic period of North America's Great Lakes region. Artifacts from some of these sites have been dated from 6500 to 1580 BCE. [1][2][page needed] It is characterized by widespread copper artifacts, including tools and weapons, as well as ornamental objects.
Metals of antiquity. German amulet to protect against disease (18th century); it is made from an alloy of the seven alchemical metals: lead, tin, iron, gold, copper, mercury and silver. The metals of antiquity are the seven metals which humans had identified and found use for in prehistoric times in Africa, Europe and throughout Asia: [1] gold ...
Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow. Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry. The alternation of abundance between even and odd atomic number is ...
The Chalcolithic (also called the Copper Age and Eneolithic) [a] was an archaeological period characterized by the increasing use of smelted copper. It followed the Neolithic and preceded the Bronze Age. It occurred at different periods in different areas, but was absent in some parts of the world, such as Russia, where there was no well ...
Copper. face-centered cubic (fcc) (cF4) Copper is a chemical element; it has symbol Cu (from Latin cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity ...