Gold prospecting is the act of searching for new

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...

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.

Prospecting for placer gold

Prospecting for placer gold is normally done with a gold pan or similar instrument to wash free gold particles from loose surface sediment. The use of gold pans is centuries old, but is still common among prospectors and miners with little financial backing. Deeper placer deposits may be sampled by trenching or drilling. Geophysical methods such as

seismic Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other ...

, gravity or magnetics may be used to locate buried river channels that are likely locations for placer gold. Sampling and assaying a placer gold deposit to determine its economic viability is subject to many pitfalls. Once placer gold is discovered, the gold pan is usually replaced by sluices or mechanical devices to wash greater volumes of material. Discovery of placer gold has often resulted in discovery of hardrock gold deposits when the placers are traced to their sources.

Prospecting for hardrock gold deposits

Prospectors for

hardrock Hard rock or heavy rock is a loosely defined subgenre of rock music typified by aggressive vocals and distorted electric guitars. Hard rock began in the mid-1960s with the garage, psychedelic and blues rock movements. Some of the earliest har ...

, or

lode In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fissure (or crack) in a rock formation or a vein of ore that is deposited or embedded between layers of rock. The current meaning (ore vein) dates from the 1 ...

gold deposits, can use many tools. It is done at the simplest level by surface examination of rock outcrops, looking for exposures of mineral veins,

hydrothermal alteration Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is the replacement of one rock by another of different mineralogical and chemical co ...

, or rock types known to host gold deposits. Field tools may be nothing more than a rock hammer and hand lens. Hardrock gold deposits are more varied in mineralogy and geology than placer deposits, and prospecting methods can be very different for different types of deposits. As with placer gold, the sophistication of methods used to prospect for hardrock gold vary with the financial resources of the prospector. Drilling is often used to explore the subsurface. Surface

geophysical Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' some ...

methods may be used to locate geophysical anomalies associated with gold deposits. Samples of rocks or soil may be collected for geochemical laboratory assay, to determine metal content or detect geochemical anomalies. Hardrock gold particles may be too small to see, even with a microscope. Most gold today is produced in large

open-pit Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow. This form of mining ...

and deep underground mines. However, small-scale gold mining is still common, especially in developing countries. A 2012 study by Australian scientists found that termites have been found to excrete trace deposits of gold. According to the CSIRO, the termites burrow beneath eroded subterranean material which typically masks human attempts to find gold, and ingest and bring the new deposits to the surface. They believe that studying termite nests may lead to less invasive methods of finding gold deposits. Herodotus reported about gold-digging ants.

Recreational prospecting

Small-scale recreational prospecting for placer gold has been seen in many parts of the world including

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

(especially in Otago), Australia,

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...

(at

Dolaucothi The Dolaucothi Gold Mines (; cy, Mwynfeydd Aur Dolaucothi) (), also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mi ...

and in Gwynedd), in

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

especially in western states but also elsewhere.

Gallery

Image:Alaska_Gold_Nugget_from_the_Blue_Ribbon_Mine.png, A gold nugget from the

Blue Ribbon Mine Gold was discovered in the Yentna-Cache Creek Mining District in the U.S. state of Alaska (also known separately as the Yentna District or Cache Creek District) of the upper Susitna River Valley in 1898, soon followed by claim staking. Placer ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...

. Image:Goldinpan.jpg, Gold nuggets in a pan also from the Blue Ribbon Mine in Alaska. Image:Oldworkings.jpg, Old workings in a drywash in southern Arizona. Image:Stringer156 nugget.jpg, Using a

metal detector A metal detector is an instrument that detects the nearby presence of metal. Metal detectors are useful for finding metal objects on the surface, underground, and under water. The unit itself, consist of a control box, and an adjustable shaft, ...

in a Southern California desert, an individual prospector found this gold nugget, known as the

Mojave Nugget The Mojave Nugget is a large gold nugget found in California, United States. It was found in the Stringer district near Randsburg by prospector Ty Paulsen in 1977 using a metal detector. The nugget, which weighs , is part of the Margie and Rober ...

, weighing . File:B.O. Holtermann with the Holtermann Nugget, North Sydney, 1874-1876 ? - American & Australasian Photographic Company (8575721367).jpg,

Bernhardt Holtermann Bernhardt Otto Holtermann (29 April 1838 – 29 April 1885) 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 sp ...

and the gold specimen "Holtermann Nugget" discovered at Star of Hope Mine in 1872

References

{{reflist

External links

USGS article on gold prospecting

Public Gold Fossicking Areas in New Zealand

Modern-Day Gold Diggers
- slideshow by ''

NPR National Public Radio (NPR, stylized in all lowercase) is an American privately and state funded nonprofit media organization headquartered in Washington, D.C., with its NPR West headquarters in Culver City, California. It differs from other ...

''
- Gold Maps, Historic Mines