Cobalt | |
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State | Ontario |
Country | Canada |
Capital | |
Population | 1128 |
Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought to be due to the known metal bismuth. Miners had long used the name kobold ore (German for goblin ore) for some of the blue-pigment-producing minerals; they were so named because they were poor in known metals, and gave poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold.
Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). The element is, however, more usually produced as a by-product of copper and nickel mining.
Luxor | |
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State | |
Country | |
Capital | |
Population | 0 |
Luxor (; Arabic: الأقصر l-aqṣur Egyptian Arabic pronunciation: [ˈloʔsˤoɾ], Upper Egyptian pronunciation: [ˈloɡsˤor]; Sahidic Coptic: ⲡⲁⲡⲉ Pape, pronounced [ˈpapə]) is a city in Upper (southern) Egypt and the capital of Luxor Governorate. The population of Luxor is 1,328,429 (2020), with an area of approximately 417 square kilometres (161 sq mi). It is among the oldest inhabited cities in the World.
The modern city includes the site of the Ancient Egyptian city of Waset, also known as Nut (Coptic: ⲛⲏ) and to the Greeks as Thebes or Diospolis, Luxor has frequently been characterized as the "world's greatest open-air museum", as the ruins of the temple complexes at Karnak and Luxor stand within the modern city.
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