Investment grade copper is at least 99.9% pure copper.
No, unlike gold, silver and platinum, copper is considered a base (or industrial) metal and not a precious metal. However, like gold, silver and platinum, copper can be classified as bullion because it is a monetary metal. Copper has served as money since money was invented. Because of this and the fact that copper has recently gained the attention of precious metal investors, a strong case can be made that copper has achieved semi-precious status.
Gold, silver and copper have been reliably used as money for thousands of years. Over the course of many centuries, these three metals have served as the money of choice in major economies around the world. The reasons have to do with the basic functions and characteristics of money which are as follows:
The Three Basic Functions of Money —
1. Medium of exchange – money facilitates transactions of goods and services in an economy
2. Unit of account – money provides a common sense measure of the value of goods and services being exchanged
3. Store of value – money needs to hold its value over time
The Characterstics of Ideal Money —
• Divisible – each unit must be precisely divisible into smaller units.
• Uniform – each unit must be precisely uniform and consistent.
• Valuable – it must be a reliable store of value over long periods of time.
• Portable – it must be easy and inexpensive to transport in large values.
• Storable – it must be easy and inexpensive to store in large values.
Copper in currency form has been proven to meet the basic functions and to have all the characteristics above, and like gold and silver it is durable, ductile, inert, malleable and attractive. It may not be as scarce as its noble metal cousins, but its supply is not unlimited and its more plentiful supply, at least at this point in time, makes it more affordable for investors and collectors.
The properties of high ductility, malleability, thermal and electrical conductivity, and its resistance to corrosion have led copper to being a major industrial metal and one of the important materials in the development of civilization. It was the first useful metal to be discovered and was for many centuries the only one available for the countless number of practical uses for which metals are required. Without copper, there might never have been an electric light or space flight. This miraculous mineral and its alloys are at the heart of all technology, from transportation to telecommunications.
Copper is more difficult to process than gold and silver. Copper oxidizes readily when molten, whereas gold and silver do not as easily, so special procedures have to be used to produce pure copper without bubbles, thus increasing its fabrication costs.
So although copper is inexpensive compared to silver and gold, the cost of fabrication is similar to bars made of the more expensive precious metals. Thus, the fabrication premium, while similar in absolute dollars for each bar, is percentage wise much higher on copper bullion bars. But the fabrication premium can be easily recovered on the secondary market, e.g. eBay, eBid.net, craigslist, direct to collectors, etc.
Use a mixture of vinegar & salt and wipe on the bar until the tarnish is gone, then dip in baking soda water to neutralize the acid. Then rinse and dry.
You can also use Twinkle Brass & Copper Cleaner, Wright's Copper Cream or e-Z-est Coin Cleaner.
Copper is the third most consumed metal after iron (steel) and aluminum.
By far the most important use of copper is in electrical wiring. Copper is second only to silver as a conductor of electricity. It corrodes very slowly and can be formed easily into thin wires. It also has many other uses including plumbing, coinage, jewelry, and metal alloys.
Yes, copper can kill or inhibit health threatening fungi, bacteria, and viruses, including water-borne organisms. Copper tubes help protect water systems from potentially lethal bacteria such as legionella. Because of its antimicrobial properties, numerous applications of copper and copper alloy products are currently being explored in the healthcare and public sanitation fields to eliminate pathogens, reduce the spread of diseases and produce clean water. Source: International Copper Study Group
The Story Of Copper: From Ore To More by Kennecott Utah Copper is a six minute video which answers this question in expert fashion.
Chile, Peru, United States, China, Australia and Indonesia are the leading producers of copper. In the USA the principal mining States are, in descending order of production: Arizona, Utah, New Mexico, Nevada, and Montana. They accounted for more than 99% of domestic production in 2009.
The world's largest copper mine is Kennecott's Bingham Canyon Mine located just west of Salt Lake City, Utah and a little south of The Great Salt Lake. It has produced more copper than any mine in history - about 18.7 million tons. The mine is 2-3/4 miles across at the top and 3/4 of a mile deep and is so big, it can be seen by the space shuttle astronauts as they pass over the United States.
Recent assessments of copper resources indicated 550 million tons of copper remain in identified and undiscovered resources in the United States. Source: U.S. Geological Survey National Mineral Resource Assessment Team, 2000, 1998 assessment of undiscovered deposits of gold, silver, copper, lead, and zinc in the United States: U.S. Geological Survey Circular 1178, 21
Copper is an important ingredient in several alloys (metals melted together):  Brass, which is copper plus zinc. A well known representative of this alloy is Jeweler's Brass, also known as "new gold" because of its color and for not tarnishing with water. Jeweler's Brass is 85% pure copper and 15% pure zinc;  Bronze, which is copper plus tin;  Sterling Silver, which is silver (at least 92.5% silver) plus copper; and  German Silver, an alloy of 65% copper plus zinc, nickel and silver that is harder than sterling silver and is often used in making "white gold".
Yes, copper is nearly 100% recyclable. It is one of the most recycled of all metals. Virtually all products made from it can be recycled. Copper can be considered as renewable since it can be recycled over and over again without losing any of its chemical or physical properties. It certainly makes economic sense to salvage as much copper as possible from a product at the end of its life cycle and re-use it. Source: International Copper Study Group
The copper Lincoln Cent minted from 1909 - 1981 has a metal composition of 95% copper and 5% zinc. At the current value of copper of over $4.00 per pound, the melt value of a penny minted in the years listed above (with the exception of the 1943 steel penny) is over 2.8 cents per penny. See this site for up-to-date coin values: www.coinflation.com.
"The natural weathering of copper is a direct consequence of the corrosive attack of airborne sulfur compounds. This leads to a gradual change in the surface color until equilibrium is reached and the change is stabilized. The final color is different and depends on the location and local weather. Salt, moisture, sunlight and orientation can effect the final color. In general, copper changes in hue from a natural salmon through a progression of russet browns, grays and finally to a blue-green or gray-green patina." --Copper Development Association
Copper does not burn, melt or release noxious or toxic fumes in the event of a fire.
The melting point of copper is 1083 °C, or 1982 °F. The boiling point is a toasty 2567.0 °C, or 4652.6 °F.
Because copper is one of the most economically sensitive commodities in the world, many investors say the metal has a PhD because of its predictive value, i.e., copper is a consensus indicator for the global economy.
London Metal Exchange
Shanghai Futures Exchange