|
Gold Nugget
A gold nugget is a naturally occurring piece of Native metal, native gold. Watercourses often concentrate nuggets and finer gold in placer deposit, placers. Nuggets are recovered by placer mining, but they are also found in residual deposits where the gold-bearing vein (geology), veins or lodes are weathered. Nuggets are also found in the tailings piles of previous mining operations, especially those left by gold mining dredges. Formation Nuggets are gold fragments weathered out of an original lode. They often show signs of abrasive polishing by stream action, and sometimes still contain inclusions of quartz or other lode matrix material. A 2007 study on Australian nuggets ruled out speculative theories of supergene (geology), supergene formation via ''in-situ'' precipitation, cold welding of smaller particles, or bacterial concentration, since crystal structures of all of the nuggets examined proved they were originally formed at high temperature deep underground (i.e., they wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baryancistrus Xanthellus
''Baryancistrus xanthellus'' is a species of Loricariidae, armored catfish endemism, endemic to Brazil. It is a benthic fresh water fish that lives in the Volta Grande and Xingu River, as well as the area immediately above Belo Monte falls and the Iriri River. It reaches a length of fish measurement, SL. It appears in the aquarium trade, where it is typically referred to either by its associated L-numbers, which are L018, L081, L085, L177, LDA60, LDA116 or LDA117; or as the gold nugget pleco. References Ancistrini Suckermouth catfish of Brazil Endemic fish of Brazil Fish described in 2011 {{Hypostominae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arizona
Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the northwest and California to the west, and shares Mexico-United States border, an international border with the Mexican states of Sonora and Baja California to the south and southwest. Its Capital city, capital and List of largest cities, largest city is Phoenix, Arizona, Phoenix, which is the most populous state capital and list of United States cities by population, fifth most populous city in the United States. Arizona is divided into 15 List of counties in Arizona, counties. Arizona is the list of U.S. states and territories by area, 6th-largest state by area and the list of U.S. states and territories by population, 14th-most-populous of the 50 states. It is the 48th state and last of the contiguous United States, contiguous states to be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canaã
Canaã (Portuguese for "Canaan") is a municipality in the state of Minas Gerais in Brazil. The population is 4,548 (2020 est.) in an area of 175 km2. See also * List of municipalities in Minas Gerais This is a list of the municipalities in the States of Brazil, state of Minas Gerais, Minas Gerais (MG), located in the Southeast Region, Brazil, Southeast Region of Brazil. Minas Gerais is divided into 853 Municipalities of Brazil, municipalities, ... References 1962 establishments in Minas Gerais Municipalities in Minas Gerais {{MinasGerais-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serra Pelada
Serra Pelada (English: "Naked Mountain Range") is a Brazilian village, district of the municipality of Curionópolis, in the southeast of Pará. Serra Pelada was a large gold mine in Brazil, south of the mouth of the Amazon River. The mine was made infamous by the still images taken by Alfredo Jaar and later by Sebastião Salgado and the first section of Godfrey Reggio's 1988 documentary '' Powaqqatsi'', showing an anthill of workers moving vast amounts of ore by hand. Because of the chaotic nature of the operation estimating the number of miners was difficult, but at least 100,000 people were thought to be present, making it one of the largest mines in the world. Today the Serra Pelada mine is abandoned and the giant open pit that was created by hand has filled with water, creating a small polluted lake. Discovery In January 1980, farmer Genésio Ferreira da Silva hired a geologist to investigate whether gold he found on his property was part of a larger deposit. A local chil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welcome Nugget
The Welcome Nugget was a large gold nugget, weighing 2,217 troy ounces 16 pennyweight. (68.98 kg), that was discovered by a group of twenty-two Cornish miners at the Red Hill Mining Company site at Bakery Hill (near the present intersection of Mair and Humffray Street) in Ballarat, Victoria, Australia, on 9 June 1858. It was located in the roof of a tunnel underground. Shaped roughly like a horse's head, it measured around long by wide and high, and had a roughly indented surface. It was assayed by William Birkmyre of the Port Phillip Gold Company and given its name by finder Richard Jeffery. Eclipsed by the discovery of the larger Welcome Stranger eleven years later in 1869 (also in Victoria), it remains the second largest gold nugget ever found. The finders had been among the first to introduce steam-driven machinery into the field at Ballarat and had looked first at nearby Creswick with no luck. Their luck changed at Bakery Hill, however, and several smaller nug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moliagul, Victoria
Moliagul is a locality in the Shire of Central Goldfields and Shire of Loddon, Victoria, Australia, located northwest of Melbourne and west of Bendigo. The area is notable for the discovery of a number of gold nuggets. These finds include the world's largest, the Welcome Stranger, which was discovered in 1869 by John Deason and Richard Oates. At the , Moliagul had a population of 80. Moliagul is composed of scattered rural dwellings and small farms, a hotel (now closed), museum, the old school (now a hall) and former church. Mount Moliagul is located in the locality. History The name Moliagul is believed to be a derivation of the Aboriginal word "moliagulk", meaning "wooded hill". In late 1852, gold was discovered in Queen's Gully and the settlement of Moliagul sprang up almost immediately. By January of the next year a thriving goldfields town with a store, a butcher's shop and a blacksmith's forge had opened but almost immediately the new settlement was abandoned as peo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welcome Stranger
Welcome Stranger is the name of the largest alluvial gold nugget ever discovered. It was unearthed by Cornwall, Cornish miners John Deason and Richard Oates on 5February 1869 in Moliagul, 9 miles north-west of Dunolly, Victoria, Dunolly in Victoria, Australia. Discovery Found only below the surface, near the base of a tree on a slope leading to what was then known as Bulldog Gully, the nugget had a gross weight of (241 lb 10 oz). Its trimmed weight was (210 lbs), and its net weight was (192 lbs 11.5 oz).Potter, Terry F. (1999) ''The Welcome Stranger: a definitive account of the worlds largest alluvial gold nugget''. At the time of the discovery, there were no scales capable of weighing a nugget this large, so it was broken into three pieces on an anvil by Dunolly-based blacksmith Archibald Walls. Deason, Oates, and a few friends took the nugget to the London Chartered Bank of Australia, in Dunolly, which advanced them Pound sterling, £9,000. Deason and Oates were fina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrum
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 "Colored gold#Green gold, 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 the Old Kingdom of Egypt, sometimes as an exterior coating to the pyramidion, pyramidia atop ancient Egyptian pyramids and obelisks. It was also used in the making of ancient Beaker (archaeology) , 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. Etymology The name ''electrum'' is the Latinized form of the Greek language, Greek word ἤλεκτρον (''ḗlektron''), mentioned in the ''Odyssey'', referring to a metallic s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element; it has symbol Cu (from Latin ) 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, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable, unalloyed metallic form. This means that copper is a native metal. This led to very early human use in several regions, from . Thousands of years later, it was the first metal to be smelted from sulfide ores, ; the first metal to be cast into a shape in a mold, ; and the first metal to be purposely alloyed with another metal, tin, to create bronze, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver
Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. Silver is found in the Earth's crust in the pure, free elemental form ("native metal, native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of the seven metals of antiquity, silver has had an enduring role in most human cultures. Other than in currency and as an in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fineness
The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of ''fine metal'' therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass. Sterling silver contains 92.5% silver and 7.5% of other metals, usually copper, by mass. Various ways of expressing fineness have been used and two remain in common use: ''millesimal fineness'' expressed in units of parts per 1,000 and '' karats'' or ''carats'' used only for gold. Karats measure the parts per 24, so that 18 karat = = 75% gold and 24 karat gold is considered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
