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Gold


Mineral Properties and Geologic Occurrence


Article by: , Ph.D., RPG


Gold nuggets

Gold Nuggets from Colorado. These specimens range between three and eight millimeters across. They have the uniform color and rounded edges common of alluvial gold particles.

What is Gold?

Native gold is an element and a mineral. It is highly prized by people because of its attractive color, its rarity, resistance to tarnish, and its many special properties - some of which are unique to gold. No other element has more uses than gold. All of these factors help support a price of gold that is higher than all but a few other metals.

Trace amounts of gold are found almost everywhere, but large deposits are found in only a few locations. Although there are about twenty different gold minerals, all of them are quite rare. Therefore, most gold found in nature is in the form of the native metal.

Gold occurs in hydrothermal veins deposited by ascending solutions, as disseminated particles through some sulfide deposits, and in placer deposits.



Physical Properties of Gold

Chemical Classification Native element
Color Golden, yellow. Whitens when naturally alloyed with silver.
Streak Golden, yellow.
Luster Metallic, without tarnish.
Diaphaneity Opaque
Cleavage None
Mohs Hardness 2.5 to 3
Specific Gravity 19.3 when pure. Specific gravity decreases as gold naturally alloys with silver, copper or other metals.
Diagnostic Properties Color, hardness, streak, specific gravity, ductility, malleability.
Chemical Composition Gold, Au
Crystal System Isometric
Uses Many uses in jewelry, coinage, and bullion. Gold is an electrical conductor used in computers, circuits, appliances, cell phones, etc. Dental work, gilding, and many other uses.

vein gold

Vein gold: White "vein quartz" with gold from Colorado. This specimen is approximately one inch (2.5 centimeters) across.

gold in quartz vein

Vein gold: Vein quartz with gold attached to basalt from California. This specimen is approximately 1 inch (2.4 centimeters) across.

Uses of Gold

2017 Gold Production
Country
Metric Tons
China440
Australia300
Russia255
United States245
Canada180
Peru155
South Africa145
Mexico110
Uzbekistan100
Brazil85
The values above are estimated gold production in metric tons. Data from USGS Mineral Commodity Summaries.

Most of the gold that is newly consumed or recycled each year is used in the production of jewelry. About 10% is used in coinage or in the financial stores of governments. The remaining 12% is consumed in a wide range of other uses which include electronics, medicine, dentistry, computers, awards, pigments, gilding, and optics. More information on the uses of gold.



World Gold Production Map

World Gold Production Map: Which countries produce the most gold? The top ten gold-producing countries are shown in green on the map above. See the chart on this page for gold production statistics for each country.


Mineral collection

The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties. Inexpensive mineral collections are available in the Geology.com Store.



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