Copper - Nugget & Native
THE HISTORY OF COPPER
Copper (Cu) is number 29 in the 'Periodic Table of Elements'. It is a metallic element that is naturally present in many substances, including rocks, soil and the human body. It also occurs naturally in a wide variety of vegetables, fruits and grains, dried beans, nuts, meats, seafoods and chocolate as well as in drinking water
Commercial sources of copper are found in deposits which formed under the earth's surface as the result of early volcanic disturbances. Primary ores, called sulfide ores, formed when molten solutions flowed into the earth's crust. Secondary ores, called oxide ores, formed as weather and other natural forces altered ancient rocks. Both types of ore are mined and processed to extract the copper. Primary ore minerals of copper include malachite, azurite, chalcocite, bornite, and cuprite. One of the more familiar and beautiful minor ore minerals of copper is chrysocolla.
About 100,000 years ago, man first discovered that using rocks and minerals could dramatically alter his life-style. The first knife and projectile points made of obsidian meant that he no longer had to use sticks and snares to capture dinner.
Today, we no longer have to forage for food like our ancient ancestors. In fact, many rocks and minerals are a regular part of dinner (halite, trona, silica) and we are still discovering new and exciting ways that they can be used to improve our standard of living. Our Rocks We Eat collection includes six rocks you come in contact with on your dinner table - some almost every day.
In fact, entire periods of world history have been named for ensuing discoveries about how to alter and utilize rocks and minerals. The STONE AGE lasted from about 100,000 years ago until roughly 6,000 BC.
Copper is the world's oldest useful metal. Its first known use - a pendant discovered in what is now northern Iraq - has been dated to about 8700 B.C. For nearly 5,000 years, copper was the only metal known to man. Prehistoric societies used copper in utensils, piping, tools, surgical instruments, weapons and ornaments. Not until about 4000 BC did gold appear on the scene as man's second metal.
Early copper artifacts, first decorative, then utilitarian, were undoubtedly hammered out from native copper - pure copper found in conjunction with copper-bearing ore deposits. By 5000 BC, the dawn of metallurgy had arrived, as evidence exists of the smelting of simple copper oxide ores such as malachite and azurite.
The "melting rocks" discovery led us into the next great age that could not have existed without rocks, minerals and mining. The BRONZE AGE was entered quite by accident with the discovery that when different types of "rocks" were melted and mixed, their physical properties could be altered in exciting ways. That experimentation heralded the birth of metallurgy - the study of the chemical and physical properties of rocks, minerals and metals - as a science. It also introduced the world to BRASS (copper and tin) and BRONZE (copper, zinc and tin), both of which we continue to use almost 8,000 years after their discovery. Today, such "mixing'' is referred to as alloying.
By 3000 B.C., silver and lead were being used and the alloying of copper had begun, first with arsenic and then with tin. For many centuries, bronze reigned supreme, being used for plows, tools of all kinds, weapons, armor, and decorative objects. We know that copper came from the island of Cyprus and numerous other sites in the Middle East. However, the origin of the tin used in early bronze is still a mystery.
The Bronze Age suddenly ended at about 1200 BC, with the general collapse of the ancient world and the interruption of international trade routes. The supply of tin in particular dried up and the Iron Age was ushered in, not because iron was a superior material, but because it was widely available. The deliberate alloying of iron with carbon to form steel did not occur for centuries.
The IRON AGE began about 1,000 BC. Melting iron requires much higher temperatures than those produced by campfires, about the only iron in use during the stone and bronze ages were highly prized pieces from meteors that had been laboriously fashioned into jewelry or spear or arrow points. The door to the new age was opened by the discovery of how to convert iron and iron ores such as hematite and magnetite into a useful metal that could be formed into tools and implements.
Large-scale mining of copper had its origins in the late 1800's, primarily in the American West. Prior to that time, many small mines existed around the country, particularly in the Upper Peninsula of Michigan and in Arizona. However, they were able to extract copper only from high-grade ores. In order to recover copper from extensive low-grade ore deposits, new and more efficient processing methods were developed around the turn of the century. Those processes made possible the economic use of large porphyry ore deposits - one in which the copper-bearing minerals are widely dispersed throughout the host rock. Most of the US production of copper comes from large porhyry deposits in Arizona and Utah. Open-pit mining techniques were developed for use on these low-grade porphyry deposits and the United States quickly became the world leader in the production of copper.
Copper plays an essential role in the daily lives of millions of people around the world. For example, every car built contains copper wiring and virtually all electronic equipment requires copper wiring to operate. You will find copper to be an integral part of virtually every modern telecommunication and transportation technology. Copper is the key element in conducting electricity from power plants to our homes and businesses.
The electrical wire mill industry started in 1877, when a Connecticut brass mill man named Thomas Doolittle developed hard-drawn copper wire strong enough to be strung overhead. Prior to that time, iron wire had been used in the telegraph system. The telephone system was commercialized quickly after its discovery in 1876 and both it and the growing electric power grid began to consume large quantities of copper wire.
Here are some other interesting facts about copper and its uses:
About 65 percent of the copper used in the United States is mined in Arizona where mining has been taking place for more than 100 years. Yet, it has affected less than 0.13 percent of Arizona's land.
Since 1963, more than 28 billion feet, or about 5.3 million miles of copper plumbing tube has been installed in U.S. buildings - equivalent to a tube wrapping around the earth 200 times.
The United States derives as much copper each year from recycled materials as from newly-found ore.