Gold prospecting is the act of searching for new

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

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.

Prospecting for placer gold

Prospecting for placer gold is normally done with a

gold pan Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

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 (or generally, quakes) and the generation and propagation of elastic ...

, 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, or

lode In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fracture (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 th ...

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 Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal c ...

hydrothermal alteration Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a Rock (geology), rock by hydrothermal and other fluids. It is traditionally defined as metamorphism which involves a change in t ...

, 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 Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

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 properties of Earth and its surrounding space environment, and the use of quantitative methods for their analysis. Geophysicists conduct investigations acros ...

methods may be used to locate geophysical anomalies associated with gold deposits. Samples of rocks or soil may be collected for

geochemical Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the ...

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 that extracts rock (geology), rock or minerals from the earth. Open-pit mines are used when deposits of commercially ...

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 ant The gold-digging ant is a mythical insect described in classical and medieval bestiaries. They were dog- or fox-sized ants that dug up gold in sandy areas. Some versions of the '' Physiologus'' said they came from Ethiopia, while Herodotus claim ...

Recreational prospecting

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

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

(especially in

Otago Otago (, ; ) is a regions of New Zealand, region of New Zealand located in the southern half of the South Island and administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local go ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

(at Dolaucothi and in

Gwynedd Gwynedd () is a county in the north-west of Wales. It borders Anglesey across the Menai Strait to the north, Conwy, Denbighshire, and Powys to the east, Ceredigion over the Dyfi estuary to the south, and the Irish Sea to the west. The ci ...

), in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

especially in western states but also elsewhere.

Gallery

Image:Alaska_Gold_Nugget_from_the_Blue_Ribbon_Mine.png, A

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 wher ...

from the Blue Ribbon Mine in

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

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. A metal detector consists of a control box, an adjustable shaft, and ...

in a Southern California

desert A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...

, an individual prospector found this

, known as the Mojave Nugget, weighing . File:B.O. Holtermann with the Holtermann Nugget, North Sydney, 1874-1876 ? - American & Australasian Photographic Company (8575721367).jpg, Bernhardt Holtermann 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) is an American public broadcasting organization headquartered in Washington, D.C., with its NPR West headquarters in Culver City, California. It serves as a national Radio syndication, syndicator to a network of more ...

''
- Gold Maps, Historic Mines