Cobalt vs Yerevan

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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.

The copper belt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. World production in 2016 was 116,000 metric tons (114,000 long tons; 128,000 short tons) (according to Natural Resources Canada), and the DRC alone accounted for more than 50%.Cobalt is primarily used in lithium-ion batteries, and in the manufacture of magnetic, wear-resistant and high-strength alloys. The compounds cobalt silicate and cobalt(II) aluminate (CoAl2O4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Cobalt occurs naturally as only one stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays. Cobalt is the active center of a group of coenzymes called cobalamins. Vitamin B12, the best-known example of the type, is an essential vitamin for all animals. Cobalt in inorganic form is also a micronutrient for bacteria, algae, and fungi.

Source: Wikipedia

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Yerevan (UK: YERR-ə-VAN, US: -⁠VAHN; Armenian: Երևան [jɛɾɛˈvɑn] (listen), sometimes spelled Erevan) is the capital and largest city of Armenia and one of the world's oldest continuously inhabited cities. Situated along the Hrazdan River, Yerevan is the administrative, cultural, and industrial center of the country. It has been the capital since 1918, the fourteenth in the history of Armenia and the seventh located in or around the Ararat plain. The city also serves as the seat of the Araratian Pontifical Diocese; the largest diocese of the Armenian Apostolic Church and one of the oldest dioceses in the world.The history of Yerevan dates back to the 8th century BC, with the founding of the fortress of Erebuni in 782 BC by King Argishti I at the western extreme of the Ararat plain. Erebuni was "designed as a great administrative and religious centre, a fully royal capital." By the late ancient Armenian Kingdom, new capital cities were established and Yerevan declined in importance. Under Iranian and Russian rule, it was the center of the Erivan Khanate from 1736 to 1828 and the Erivan Governorate from 1850 to 1917, respectively. After World War I, Yerevan became the capital of the First Republic of Armenia as thousands of survivors of the Armenian Genocide in the Ottoman Empire arrived in the area. The city expanded rapidly during the 20th century as Armenia became part of the Soviet Union. In a few decades, Yerevan was transformed from a provincial town within the Russian Empire to Armenia's principal cultural, artistic, and industrial center, as well as becoming the seat of national government.

With the growth of the Armenian economy, Yerevan has undergone major transformation. Much construction has been done throughout the city since the early 2000s, and retail outlets such as restaurants, shops, and street cafés, which were rare during Soviet times, have multiplied. As of 2011, the population of Yerevan was 1,060,138, just over 35% of the Republic of Armenia's total population. According to the official estimate of 2016, the current population of the city is 1,073,700. Yerevan was named the 2012 World Book Capital by UNESCO. Yerevan is an associate member of Eurocities.Of the notable landmarks of Yerevan, Erebuni Fortress is considered to be the birthplace of the city, the Katoghike Tsiranavor church is the oldest surviving church of Yerevan and Saint Gregory Cathedral is the largest Armenian cathedral in the world, Tsitsernakaberd is the official memorial to the victims of the Armenian Genocide, and several opera houses, theatres, museums, libraries, and other cultural institutions. Yerevan Opera Theatre is the main spectacle hall of the Armenian capital, the National Gallery of Armenia is the largest art museum in Armenia and shares a building with the History Museum of Armenia, and the Matenadaran repository contains one of the largest depositories of ancient books and manuscripts in the world.

Source: Wikipedia