A gold nugget is a naturally occurring piece of native gold. Watercourses often concentrate nuggets and finer gold in placers. Nuggets are recovered by placer mining, but they are also found in residual deposits where the gold-bearing veins or lodes are weathered. Nuggets are also found in the tailings piles of previous mining operations, especially those left by gold mining dredges.
Nuggets are gold fragments weathered out of an original lode. [1] 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 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 were of hypogene origin). [2] [3]
Other precious metals such as platinum form nuggets in the same way. A later study of native gold from Arizona, US, based on lead isotopes indicates that a significant part of the mass in alluvial gold nuggets in this area formed within the placer environment. [4]
Nuggets are usually 20K to 22K purity (83% to 92% by mass). Gold nuggets in Australia often are 23K or slightly higher, while Alaskan nuggets are usually at the lower end of the spectrum. Purity can be roughly assessed by the nugget color, the richer and deeper the orange-yellow the higher the gold content. Nuggets are also referred to by their fineness, for example "865 fine" means the nugget is 865 parts per thousand in gold by mass. The common impurities are silver and copper. Nuggets high in silver content constitute the alloy electrum. [5] The chemical composition of supergene gold nuggets can reveal the characteristics of the primary ore. [6]
Two gold nuggets are claimed as the largest in the world: the Welcome Stranger and the Canaã nugget, the latter being the largest surviving natural nugget. Considered by most authorities to be the biggest gold nugget ever found, the Welcome Stranger was found at Moliagul, Victoria, Australia in 1869 by John Deason and Richard Oates. It weighed gross, over 2,520 troy ounces (78 kg; 173 lb) and returned over 2,284 troy ounces (71.0 kg; 156.6 lb) net. [7] The Welcome Stranger is sometimes confused with the similarly named Welcome Nugget, which was found in June 1858 at Bakery Hill, Ballarat, Australia by the Red Hill Mining Company. The Welcome weighed 2,218 troy ounces (69.0 kg; 152.1 lb). It was melted down in London in November 1859. [8]
The Canaã nugget, also known as the Pepita Canaa, was found on September 13, 1983, by miners at the Serra Pelada Mine in the State of Para, Brazil. Weighing 1,955 troy ounces (60.8 kg; 134.1 lb) gross, and containing 1,682.5 troy ounces (52.33 kg; 115.37 lb) of gold, [9] [10] it is among the largest gold nuggets ever found, [11] [12] and is, today, the largest in existence. The main controversy regarding this nugget is that the excavation reports suggest that the existing nugget was originally part of a nugget weighing 5,291.09 troy ounces (165 kg; 363 lb) that broke during excavations. [13] The Canaã nugget is displayed at the Banco Central Museum in Brazil along with the second and third largest nuggets remaining in existence, weighing respectively 1,506.2 troy ounces (46.85 kg; 103.28 lb) and 1,393.3 troy ounces (43.34 kg; 95.54 lb), which were also found at the Serra Pelada region. [14]
The largest gold nugget found using a metal detector is the Hand of Faith, weighing 875 troy ounces (27.2 kg; 60.0 lb), found in Kingower, Victoria, Australia in 1980.
Historic large specimens include the crystalline "Fricot Nugget", weighing 201 troy ounces (6.3 kg; 13.8 lb) – the largest one found during the California Gold Rush. It is on display at the California State Mining and Mineral Museum.
The largest gold nugget ever found in California weighed 1,593 troy ounces (49.5 kg; 109.2 lb). It was found in August 1869 in Sierra Buttes by five partners – W.A. Farish, A. Wood, J. Winstead, F.N.L. Clevering and Harry Warner. [15]
The Victoria, Australia gold rush of the early 1850s produced a number of large nuggets. They include the Welcome Nugget which weighed 68.98 kilograms (152.1 lb) which is considered to be the second largest gold nugget ever found. [16] [17] [18] Another find, the Lady Hotham, which weighed 98.5 pounds (44.7 kg), was found by a group of nine miners on September 8, 1854, in Canadian Gully, Ballarat at a depth of 135 feet. [19] The Lady Hotham was named after the wife of the Governor, Sir Charles Hotham who happened to be visiting the area when the nugget was found. Eighteen months earlier, in January and early February 1853, three other large nuggets weighing 134 pounds (61 kg), 93.125 pounds (42.241 kg), and 83.5 pounds (37.9 kg) were also found in Canadian Gully at a depth of 55 to 60 feet (17 to 18 m). [15] [20] Another nugget, the Heron, was found in 1855 in Golden Gully in the Mount Alexander goldfield. It weighed 1,008 troy ounces (31.4 kg; 69.1 lb) and was found by a group of inexperienced miners who had received a supposedly empty claim. The miners found the nugget on their second day of digging; the nugget was named after one of the gold commissioners, a Mr. Heron. [21]
On 16 January 2013, a large gold nugget was found near the city of Ballarat in Victoria, Australia by an amateur gold prospector. The Y-shaped nugget weighed slightly more than 5 kilograms (11 lb), measured around 22 cm high by 15 cm wide, and has a market value slightly below 300,000 Australian dollars, though opinions have been expressed that it could be sold for much more due to its rarity. The discovery has cast doubt on the common rumour that Victoria's goldfields were exhausted in the 19th century. [22] [23]
The Eureka Rebellion was a series of events involving gold miners who revolted against the British administration of the colony of Victoria, Australia during the Victorian gold rush. It culminated in the Battle of the Eureka Stockade, which took place on 3 December 1854 at Ballarat between the rebels and the colonial forces of Australia. The fighting left at least 27 dead and many injured, most of the casualties being rebels. There was a preceding period beginning in 1851 of peaceful demonstrations and civil disobedience on the Victorian goldfields. The miners had various grievances, chiefly the cost of mining permits and the officious way the system was enforced.
The Victorian gold rush was a period in the history of Victoria, Australia, approximately between 1851 and the late 1860s. It led to a period of extreme prosperity for the Australian colony, and an influx of population growth and financial capital for Melbourne, which was dubbed "Marvellous Melbourne" as a result of the procurement of wealth.
Sovereign Hill is an open-air museum in Golden Point, a suburb of Ballarat, Victoria, Australia. Sovereign Hill depicts Ballarat's first ten years after the discovery of gold there in 1851 and has become a nationally acclaimed tourist attraction. It is one of Victoria's most popular attractions and Ballarat's most famous.
The California State Mining and Mineral Museum is a museum of the state park system of California, United States. The museum exhibits and interprets the state's mineral resources and mining heritage. It is located in Mariposa, a city in central California, on the Mariposa County fairgrounds.
Gold prospecting is the act of searching for new gold deposits. Methods used vary with the type of deposit sought and the resources of the prospector. Although traditionally a commercial activity, in some developed countries placer gold prospecting has also become a popular outdoor recreation. Gold prospecting has been popular since antiquity. From the earliest textual and archaeological references, gold prospecting was a common thread for gaining wealth.
The Welcome Stranger is the biggest alluvial gold nugget that has ever been found, metres north-west of Dunolly.
The Hand of Faith is a gold nugget of fine-quality that was found by Kevin Hillier using a metal detector near Kingower, Victoria, Australia on 26 September 1980. Weighing 875 troy ounces, the gold nugget was only 12 inches (30 cm) below the surface, resting in a vertical position. The announcement of the discovery occurred at a press conference, attended by Premier of Victoria Dick Hamer, in Melbourne on 8 October 1980. Kovac's Gems & Minerals was appointed as the agent for the sale of the huge nugget by Hillier. It was sold to the Golden Nugget Casino chain for over a million dollars.
In the United States, gold mining has taken place continually since the discovery of gold at the Reed farm in North Carolina in 1799. The first documented occurrence of gold was in Virginia in 1782. Some minor gold production took place in North Carolina as early as 1793, but created no excitement. The discovery on the Reed farm in 1799 which was identified as gold in 1802 and subsequently mined marked the first commercial production.
Tarnagulla is a town in central Victoria, Australia. The town is in the Shire of Loddon local government area, 183 kilometres (114 mi) north west of the state capital, Melbourne. At the 2011 census, Tarnagulla had a population of 304. By 2016, the population was 133.
Talbot is a town in Victoria, Australia. At the 2016 census, Talbot had a population of 442.
Gold mining in Alaska, a state of the United States, has been a major industry and impetus for exploration and settlement since a few years after the United States acquired the territory in 1867 from the Russian Empire. Russian explorers discovered placer gold in the Kenai River in 1848, but no gold was produced. Gold mining started in 1870 from placers southeast of Juneau, Alaska.
The Carolina Gold Rush, the first gold rush in the United States, followed the discovery of a large gold nugget in North Carolina in 1799, by a 12-year-old boy named Conrad Reed. He spotted the nugget while playing in Meadow Creek on his family's farm in Cabarrus County, North Carolina. Conrad took the 17-pound (7.7 kg) gold nugget home to show his father. However, gold was not commonly seen in their community and the value of the nugget was not understood. The nugget was used as a door stop in the family's home for several years. In 1802, Conrad's father, John Reed, showed the rock to a jeweler, who recognized it as gold and offered to buy it. Reed, still unaware of the real value of his "doorstop," sold it to the jeweler for US$3.50.
The Ruby–Poorman mining district in the U.S. state of Alaska produced nearly a half million ounces of gold, all from placer mines. Some of the largest gold nuggets found in Alaska are from the district, which lies along the Yukon River. The placers are mostly deeply buried, and most were originally worked with shafts and drifts. Dozens of creeks in the district were mined, many more bear gold prospects. Cassiterite, platinum, scheelite, allanite, and native bismuth have been recovered along with gold from placer mines in the district.
Recreational gold mining and prospecting has become a popular outdoor recreation in a number of countries, including New Zealand, Australia, South Africa, Wales, in Canada and in the United States especially. Recreational mining is often small-scale placer mining but has been challenged for environmental reasons. The disruption of old gold placer deposits risks the reintroduction of post gold rush pollution, including mercury in old mining deposits and mine tailings.
Bernhardt Otto Holtermann was a successful gold miner, businessman, politician and photographer in Australia. Perhaps his greatest claim to fame is his association with the Holtermann Nugget, the largest gold specimen ever found, 59 inches (1.5 m) long, weighing 630 pounds (290 kg) and with an estimated gold content of 3,000 troy ounces (93 kg), found at Hill End, near Bathurst, New South Wales. This gave him the wealth to build a mansion in North Sydney, which is now one of the boarding houses at Sydney Church of England Grammar School.
Serra Pelada is a Brazilian village, district of the municipality of Curionópolis, in the southeast of Pará.
The Welcome Nugget is 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 in Ballarat, Victoria, Australia, on 9 June 1858. It was located in the roof of a tunnel 55 metres underground. Shaped roughly like a horse's head, it measured around 49 cm (19 in) long by 15 cm (5.9 in) wide and 15 cm (5.9 in) 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, it remains the second largest gold nugget ever found.
During the Australian gold rushes, starting in 1851, significant numbers of workers moved from elsewhere in Australia and overseas to where gold had been discovered. Gold had been found several times before, but the colonial government of New South Wales had suppressed the news out of the fear that it would reduce the workforce and destabilise the economy.
The following is a timeline of the Eureka Rebellion.
