Copper Fact Sheets

Copper — the “Red Metal — is a naturally occurring element.  It is a reddish brown nonferrous mineral which has been used for thousands of years by many cultures. Modern life has a number of applications, ranging from coins to pigments, and demand for it remains high, especially in industrialized nations. Many consumers interact with the metal in various forms on a daily basis.

History And Properties
The name for the metal comes from Kyprios, the Ancient Greek name for Cyprus, an island which had highly productive copper mines in the Ancient world. The atomic number is 29, placing it among the transition metals. The metal is highly conductive of both electricity and heat, and many of its uses take advantage of this quality. Copper can be found in numerous electronics and in wiring.

Archaeological evidence suggests that copper is among the earliest metals used by humans. Numerous digs all over the world indicate that it was used to make utensils, jewelry, and weapons. The metal is highly ductile, meaning that it can be easily worked and pulled into wire.

In addition to being useful in manufacturing, copper is also a vital dietary nutrient, although only small amounts of the metal are needed for well-being. This metal is a popular metal used in cookware because it is highly conductive, evenly transferring heat through foods. The metal will prevent hot spots that can burn food on one side of the pan. Its cookware is also very attractive and stands out in a kitchen. Some people use copper pots for decoration and not for cooking.

One interesting property is its naturally-occurring germicidal effect. Many pathogens are killed by any alloy containing more than 65 percent within a period of eight hours. Colder temperatures cause this time frame to be extended. This fact is highly useful in settings such as hospitals, which are responsible for many cases of acquired infections each year. By simply covering surfaces with copper(CAS No. 7440-50-8) alloys, the rate of infection can be decreased.

In a natural state, copper is rarely found pure. It is compounded with other elements, and the material must be treated before it can be sold. This can lead to serious environmental problems, especially when mining companies engage in unsound practices. The chemicals used to extract it can be toxic, as can the discarded elements and runoff associated with the purification. Many countries attempt to regulate their industries, to prevent widespread pollution and the problems associated with it.

How To Clean Copper?

Copper may be tough, but it’s also temperamental and changeable. It is an active metal that oxidizes quickly. This oxidation causes a bright new copper penny to quickly turn a dull brown, and an even older copper penny to form a black or green layer of oxidation. Different items may need different treatment; for instance, a copper coin may lose some or all of its value if careless cleaning causes even slight damage to the coin’s surface, but a copper pot may benefit from a good acid dip. Take your copper item into consideration when selecting a cleaning method.

Non-Chemical Methods
Try cleaning your copper using some unlikely non-chemical methods for removing discoloration. One of these involves soaking your piece in grape-seed or olive oil. As it is possibly the gentlest of methods, it can take a long time, up to a year, to see a difference. Obviously, reserve this method for the most valuable of copper items to which no damage should be done. Other options include using an eraser to gently rub at the copper, or using a toothpick, bone stylus or soft toothbrush to scrub at dirty copper.

To clean copper, however, it isn’t necessary to go as far as the hardware store. Most of the supplies to do the job can be found in your pantry, and what sound like folk remedies often turn out to be quite effective. Ketchup, lemon, vinegar, and salt? All come highly recommended as agents to clean copper, when used in the right way.

Homemade Copper Cleaner
Mix up your own quick copper cleaning solution by making a paste out of lemon juice and baking soda, lemon juice and cream of tartar, or flour, salt and vinegar. The paste should be thick enough to stick to your copper surface, but thin enough to rub in without following your cloth. Omit the flour if you would rather make a bath for the copper, using just salt and vinegar.

Closer to home, it’s important to remember that copper or brass utensils are often coated with a clear lacquer. If the item is intended for decorative use only, that is a plus, because the lacquer is designed to resist tarnishing. If the item is to be used for cooking, or will come into contact with hot water, however, the lacquer should be removed. That can be accomplished by immersing the item in a solution of boiling water and baking soda.

To clean it once the lacquer is removed, the application of a paste consisting of flour, salt and lemon juice or vinegar can be quite effective. Even ketchup, when smeared on a copper utensil, will remove tarnish, thanks to the vinegar in its makeup. Rochelle salt (potassium sodium tartrate) is another possibility when combined with caustic soda(also known as  sodium hydroxide (NaOH),the CAS number is 1310-73-2), while white vinegar and salt is a means of restoring the shine to copper pennies dulled over time.

How To Choose
The best way to decide which method is right for you is to begin with the mildest and work your way up the list. Non-chemical methods are a good place to start, and allow you to gauge the extent of oxidation. If they prove ineffective, try some of the homemade formulas.