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Roger Weller, geology instructor                     

Christina Lancaster
Physical Geology
Fall 2005

                                                                                                  All About Gold


What is it?

            Gold is derived from the Latin word aurum and is known as the symbol Au on the periodic table of elements. Only the purest gold is very soft and flexible, which easily can be hammered to a thickness of 0.000005 inches and be turned into wire that is 62 miles long. Most gold is a bright yellow and is high in luster (very glossy).  Other gold, which is finely divided, is black and just small droplets of gold can range in color from ruby red to purple.

            Heat, air, moisture, and most solvents do not affect gold. However, mixtures that are extremely watery and containing several halogens, such as chlorides and iodides, will dissolve gold. The melting point for gold is at about 1947˚ F and boils at around 5173˚ F.


Ancient History

 Fossil experts have observed that bits of natural gold had been discovered in Spanish Caves used by the Paleolithic Man about 40,000 BC.  However, the first know use of gold dates back to 4000 BC in areas of central and eastern Europe.  Archaeologists have discovered jewelry and art objects dating back to 3000 BC that were located in royal tombs in southern Iraq.  Later the Egyptians used gold to please their kings in life and death and by 1500 BC, gold was introduced to the international trade business. Around 1200 BC in Peru goldsmiths made ornaments by stamping and hammering gold.  


Credit photo to Latin American Studies:


Recent History Ė Value and Production 

With gold valued at $19.30 per troy ounce, the U.S. congress, in 1792, adopted a bimetallic standard for the nationís new currency.  In 1834, the price of gold rose to $20.67 and remained at that price for the next 100 years. Franklin Delano Roosevelt, in 1934, devalued the dollar by raising the price of gold to $35 per ounce.  Over the next 46 years, the price of gold per ounce rose dramatically, until about 1980 when it hit an all time high of $850 per ounce. Since 1980, gold prices have been in a downtrend for more than 13 years.

The production of gold dates back to the Etruscan, Minoan, Assyrian, and Egyptian civilizations when placer gold was adopted from alluvial sands and gravels by the process of washing or panning.

Around the time that the Americas were discovered, the total gold stock value of Europe was probably less than $225 million.  From the end of the 15th century to about 1850, the world product of gold totaled at 150 million troy ounces. During that time, South America and Mexico became extremely large producers of gold.  Because of Spainís domination in South America in the 16th century, the production of gold in the New World increased by a large margin. This large increase is also due to the fact of the simple seizure of gold from the Native Americans.  In 1851, the discovery of gold happened in Australia. 

In the middle of the 19th century, the United States rose up in gold production.  Gold of the United States only produced in two regions: the eastern region along the Appalachian Mountains, and the western region along the Rocky Mountains and Sierra Nevada, Coast, and Cascade Range.  Gold first shipped to the U.S. Mint for the making of coins was from North Carolina in 1804. In 1848, American Pioneer, John Sutter, made the discovery of gold in California. It was not until long after that the Gold Rush hit, which caused many prospectors from all of over the world to travel to California. In 1911, gold was discovered in Alaska, from the boundary of the Canadian border to the Sixty Mile River. Todayís leading supplier of gold is Africa, which was producing 376 metric tons in 2003.  About 70 countries, today, produce gold in wholesale quantities, but two thirds of the total worldwide production comes from South Africa, the United States, Australia, China, Canada, and Russia.


Where does gold occur?

            Though scarce, gold is widely distributed through out earth, being that it is 75th in order of abundance of the elements in the crust of Earth. Gold occurs in seawater in weight 5 to 250 parts to 100 million parts of water. However, due to the 9 billion metric tons of gold present in seawater, the cost of recovery would be greater than the value of the gold that could be recovered.  Gold occurs usually in association with silver or other metals, in quartz veins or lodes, which are not visible because of being so finely diffused. 

            Even though gold is rare, geologic processes concentrate the gold to form profitable deposits of two principal types: lode and place deposits. Lode (primary) deposits are the main points for the prospector seeking gold around and/or in the site of deposition from mineralizing solutions. A concern for prospectors or miners that are interested in a lode deposit of gold are that they must determine the average gold content per ton of mineralized rock and the size of the deposit. Placer deposits appear as concentrations of gold derived from primary deposits by erosion, wearing down or decomposition of the surrounding rock. These deposits formed in the same way throughout Earthís history. Surface placer deposits may be found under rock debris due to weathering and erosion.

Sum2005-158xlizedCAgold.jpg (59974 bytes)

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Credit Photos to the Mineral Gallery:


What are the uses of gold?

            Throughout history gold has been highly valued, not just because of its beauty, but because it is easier to work with than other metals.  A majority of the gold is used in coinage, jewelry, and art. It has also been used in the world of medicine, since 1927. In that time, it was discovered to be extremely useful in the treatment of rheumatoid arthritis. Before that time it was used in dentistry, in fillings and false teeth. Gold is used in lasers, which help surgeons to seal wounds quickly or treat used-to-be inoperable heart conditions. Below are several other major uses of gold.

         In 1908, the Olympic gold medal was first presented. The gold medal used today is actually made of silver and with at least six grams of pure gold.

         In the Galileo space probe, onboard computers are protected from short circuiting using Heavy Ion conductors made of not only silicon, but also gold.

         The robot, the Pathfinder, which took close-up pictures, used a high tech gold circuitry to transmit information back to Earth. 

         Every telephone contains gold in the small transmitter in its mouthpiece.

         Airforce One, the airplane used by the U.S. president, uses gold-plated reflectors to protect it from heat-seeking missiles.

         The World Cup trophy is 32 cm high and is made of solid 18-carat gold.


Gold has been used in a variety of ways throughout history and in many cultures. Gold will continue to be valued by most cultures as a precious and valuable commodity. 




Works Cited