It is believed that around a hundred million years ago, as a result of violent shifts on the surface of the Earth, volcanic eruptions in the form of molten rocks containing Gold, rose to the earth's surface. It cooled to form extensive veins of gold. Though it's existence is everywhere around us, there are few parts where gold can be mined economically. About 17 tonnes of ore has to be extracted to get 1 ounce of gold. There are two techniques to recover gold from the earth's surface, first from alluvial deposits in rivers and the other is by mining it. The deepest gold mines are about 4 Km. below the Earth's surface. Today, worldwide production amounts to over 2,000 tones annually. Although gold is mined in 50 countries, South Africa is the world's single largest producer. The other major producers are United States, Russia, Australia, Canada, China, Ghana and Latin America.

The kind of gold deposits which can be termed as valuable are "placers" and "lodes or reef". Placers, from the Spanish placer, and the French placer meaning "Sand bank" or "alluvial deposit". It is obtained in the alluvial or glacial deposits of sand and gravel, often occurring in and around river and streams. The size of gold particles range from fine dust to flakes, spangles or nuggets. Placer mines today account for about 25% of the gold mined in the U.S.

Today, reef or vein are synonymous. Reef gold is gold solidly embedded as irregular dendrite masses in matrix of hard rocks. The gold in such deposits may or may not be easily visible. Load-bearing rock can extend for much more than a mile into the Earth's surface. Other metals are usually found combined with gold, especially silver, copper, lead, nickel, platinum, uranium and zinc.