Mineral Properties and Geologic Occurrence
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.|
|Luster||Metallic, without tarnish.|
|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|
|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: White "vein quartz" with gold from Colorado. This specimen is approximately one inch (2.5 centimeters) across.
Vein gold: Vein quartz with gold attached to basalt from California. This specimen is approximately 1 inch (2.4 centimeters) across.
Uses of Gold
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: 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.
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 Store.