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Electrum On Quartz Telluride (cropped)
Electrum is a naturally occurring alloy of gold and silver, with trace amounts of copper and other metals. Its color ranges from pale to bright yellow, depending on the proportions of gold and silver. It has been produced artificially, and is also known as "green gold".Emsley, John (2003Nature's building blocks: an A–Z guide to the elements Oxford University Press. . p. 168 Electrum was used as early as the third millennium BC in Old Kingdom of Egypt, sometimes as an exterior coating to the pyramidions atop ancient Egyptian pyramids and obelisks. It was also used in the making of ancient drinking vessels. The first known metal coins made were of electrum, dating back to the end of the 7th century or the beginning of the 6th century BC. For several decades, the medals awarded with the Nobel Prize have been made of gold-plated green gold. Etymology The name "electrum" is the Latinized form of the Greek word ἤλεκτρον (''ḗlektron''), mentioned in the ''Odyssey' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrum On Quartz Telluride (cropped)
Electrum is a naturally occurring alloy of gold and silver, with trace amounts of copper and other metals. Its color ranges from pale to bright yellow, depending on the proportions of gold and silver. It has been produced artificially, and is also known as "green gold".Emsley, John (2003Nature's building blocks: an A–Z guide to the elements Oxford University Press. . p. 168 Electrum was used as early as the third millennium BC in Old Kingdom of Egypt, sometimes as an exterior coating to the pyramidions atop ancient Egyptian pyramids and obelisks. It was also used in the making of ancient drinking vessels. The first known metal coins made were of electrum, dating back to the end of the 7th century or the beginning of the 6th century BC. For several decades, the medals awarded with the Nobel Prize have been made of gold-plated green gold. Etymology The name "electrum" is the Latinized form of the Greek word ἤλεκτρον (''ḗlektron''), mentioned in the ''Odyssey' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medal
A medal or medallion is a small portable artistic object, a thin disc, normally of metal, carrying a design, usually on both sides. They typically have a commemorative purpose of some kind, and many are presented as awards. They may be intended to be worn, suspended from clothing or jewellery in some way, although this has not always been the case. They may be struck like a coin by dies or die-cast in a mould. A medal may be awarded to a person or organisation as a form of recognition for sporting, military, scientific, cultural, academic, or various other achievements. Military awards and decorations are more precise terms for certain types of state decoration. Medals may also be created for sale to commemorate particular individuals or events, or as works of artistic expression in their own right. In the past, medals commissioned for an individual, typically with their portrait, were often used as a form of diplomatic or personal gift, with no sense of being an award for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hellenistic Period
In Classical antiquity, the Hellenistic period covers the time in Mediterranean history after Classical Greece, between the death of Alexander the Great in 323 BC and the emergence of the Roman Empire, as signified by the Battle of Actium in 31 BC and the conquest of Ptolemaic Egypt the following year. The Ancient Greek word ''Hellas'' (, ''Hellás'') was gradually recognized as the name for Greece, from which the word ''Hellenistic'' was derived. "Hellenistic" is distinguished from "Hellenic" in that the latter refers to Greece itself, while the former encompasses all ancient territories under Greek influence, in particular the East after the conquests of Alexander the Great. After the Macedonian invasion of the Achaemenid Empire in 330 BC and its disintegration shortly after, the Hellenistic kingdoms were established throughout south-west Asia ( Seleucid Empire, Kingdom of Pergamon), north-east Africa ( Ptolemaic Kingdom) and South Asia ( Greco-Bactrian Kingdom, Indo-Greek ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mytilene
Mytilene (; el, Μυτιλήνη, Mytilíni ; tr, Midilli) is the capital of the Greek island of Lesbos, and its port. It is also the capital and administrative center of the North Aegean Region, and hosts the headquarters of the University of the Aegean. It was founded in the 11th century BC. Mytilene is one of the two municipalities on the island of Lesbos, created in 2019; the other is West Lesbos. Mytilene is built on the southeast edge of the island. It is the seat of a metropolitan bishop of the Eastern Orthodox Church. History As an ancient city, lying off the east coast, Mytilene was initially confined to a small island just offshore that later was joined to Lesbos, creating a north and south harbor. The early harbors of Mytilene were linked during ancient times by a channel 700 m long and 30 m wide. The Roman writer Longus speaks of white stone bridges linking the two sides. The Greek word εὔριπος ''eúripos'' is a commonly-used term when referring to a st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phocaea
Phocaea or Phokaia (Ancient Greek: Φώκαια, ''Phókaia''; modern-day Foça in Turkey) was an ancient Ionia Ionia () was an ancient region on the western coast of Anatolia, to the south of present-day Izmir. It consisted of the northernmost territories of the Ionian League of Greek settlements. Never a unified state, it was named after the Ionian ...n Ancient Greece, Greek city on the western coast of Anatolia. Colonies in antiquity, Greek colonists from Phocaea founded the colony of Massalia (modern-day Marseille, in France) in 600 BC, Emporion (modern-day Empúries, in Catalonia, Spain) in 575 BC and Elea (modern-day Velia, in Campania, Italy) in 540 BC. Geography Phocaea was the northernmost of the Ionian cities, on the boundary with Aeolis. It was located near the mouth of the river Hermus (now Gediz River, Gediz), and situated on the coast of the peninsula separating the Gulf of Cyme (Aeolis), Cyme to the north, named for the largest of the Aeolis, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). They have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium and its congener platinum is used in catalytic converters, which convert as much as 90% of the harmful gases in automobile exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into nontoxic substances (nitrogen, carbon dioxide and water vapor). Palladium is also used in electronics, dentistry, medicine, hydrogen purification, chemical applications, groundwate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for ~80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity. Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Consequent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere. Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores. Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classified as an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Gold
Pure gold is slightly reddish yellow in color, but colored gold in various other colors can be produced by alloying gold with other elements. Colored golds can be classified in three groups: * Alloys with silver and copper in various proportions, producing white, yellow, green and red golds. These are typically malleable alloys. * Intermetallic compounds, producing blue and purple golds, as well as other colors. These are typically brittle, but can be used as gems and inlays. * Surface treatments, such as oxide layers. Pure 100% (in practice, 99.9% or better) gold is 24 karat by definition, so all colored golds are less pure than this, commonly 18K (75%), 14K (58.5%), 10K (41.6%), or 9K (37.5%). Alloys White gold White gold is an alloy of gold and at least one white metal (usually nickel, silver, or palladium). Like yellow gold, the purity of white gold is given in karats. White gold's properties vary depending on the metals used and their proportions. As a result, white gold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatics
Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber, (), was thus the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law. Even though electrostatically induced forces seem to be rather weak, some electrostatic forces are relatively large. The force between an electron and a proton, which together make up a hydrogen atom, is about 36 orders of magnitude stronger than the gravitational force acting between them. There are many examples of electrostatic phenomena, from those as simple as the attraction of plastic wrap to one's hand after it is removed from a package, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amber
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia of New Jersey'', Rutgers University Press, . Amber is used in jewelry and has been used as a healing agent in folk medicine. There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as inclusions. Amber occurring in coal seams is also called resinite, and the term ''ambrite'' is applied to that found specifically within New Zealand coal seams. Etymology The English word ''amber'' derives from Arabic (ultimately from Middle Persian ''ambar'') via Middle Latin ''ambar'' and Middle French ''ambre''. The word was adopted in Middle English in the 14th century ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odyssey
The ''Odyssey'' (; grc, Ὀδύσσεια, Odýsseia, ) is one of two major Ancient Greek literature, ancient Greek Epic poetry, epic poems attributed to Homer. It is one of the oldest extant works of literature still widely read by modern audiences. As with the ''Iliad'', the poem is divided into 24 books. It follows the Greek hero cult, Greek hero Odysseus, king of Homer's Ithaca, Ithaca, and his journey home after the Trojan War. After the war, which lasted ten years, his journey lasted for ten additional years, during which time he encountered many perils and all his crew mates were killed. In his absence, Odysseus was assumed dead, and his wife Penelope and son Telemachus had to contend with a Suitors of Penelope, group of unruly suitors who were competing for Penelope's hand in marriage. The ''Odyssey'' was originally composed in Homeric Greek in around the 8th or 7th century BCE and, by the mid-6th century BCE, had become part of the Greek literary canon. In Classic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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