LCB Metals & Glass Since 1993
Gold is a heavy, yellow, metallic chemical element. It is a precious metal, with a high degree of ductility and malleability, that is used in the manufacture of a wide range of products including  jewelry, electronics, and coinage. It's chemical symbol is AU, from aurora, translating to "shining dawn". Gold was first legalized as money as early as 1091 BC in China as an alternative to silk, and is still the only universally accepted medium of exchange. Millions of people all over the world continue to use gold as a hedge against inflation and as a basic form of savings and a reliable store of value during times of economic uncertainty or political upheaval. Gold is the most non-reactive of all metals---it is benign in all natural and industrial environments. Gold never reacts with oxygen (one of the most active elements), which means it will not rust or tarnish.

Gold is among the most electrically conductive of all metals. Since electricity is basically the flow of charged particles in a current, metals that are conductive allow this current to flow unimpeded. Gold is able to convey even a tiny electrical current in temperatures varying from -55° to +200° centigrade.Gold is the most ductile of all metals, allowing it to be drawn out into tiny wires or threads without breaking. As a result, a single ounce of gold can be drawn into a wire five miles long. Gold's malleability is also unparalleled. It can be shaped or extended into extraordinarily thin sheets. For example, one ounce of gold can be hammered into a 100 square foot sheet. Gold is also one the most dense metals. A cubic foot of gold weighs about 1000 pounds. Given it's invulnerability to other elements, most all gold ever mined is still around today, in one application or another, as jewelry, tooth fillings, artwork, in architecture or electronics, coins, or bullion. In fact, all the gold mined so far would only amount to about 125,000 tons of metal, something that could be loaded on a standard freighter. Gold is the most reflective and least absorptive material of infrared (or heat) energy. High purity gold reflects up to 99% of infrared rays. Gold is also an excellent conductor of thermal energy or heat. Since many electronic processes create heat, gold is necessary to transfer heat away from delicate instruments. For example, a 35% gold alloy is used in the main engine nozzle of the Space Shuttle, where temperatures can reach 3300° centigrade. Gold alloy is the most tenacious and long-performing material available for protection at these temperatures.

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Gold Filled: Also called gold overlay, but not plated, gold filled consists of a layer, between 10K and 18K gold, permanently bonded by heat and pressure to one or more surfaces of a support metal, usually brass, then rolled or drawn to a prescribed thickness. The karat gold must be at least 1/20 by weight of the total metal content. A strong alloy that retains it's beauty and shape, and lasts a lifetime.

Gold Plate: Material consisting of a layer of plating of 10-karat gold or better which is mechanically bonded to a base metal. The karat gold content may be less than 1/20 but must be properly identified by weight in terms of total metal content. This is not an alloy. The surface of the bonded piece is subject to abrasion.

Vermeil: Gold at least 15-micro-inches thick, plated onto sterling silver by an electrolytic or mechanical process. See more about vermeil.

Gold Leaf: Pure gold that is pounded into sheets applied to other surfaces by hand. Usually about 3 micro-inches thick. Best used on items that receive little or no daily wear.

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Pure gold is too soft for jewelry and is extremely subject to rapid abrasion. Therefore, other metals are combined with it to make it harder, to produce a cheaper alloy of a specific quality, or one having a distinct color. For identification and quality control, the percentages of gold for each alloy are standardized, but the amount of the non-gold alloys are not. K, (karat), is the symbol used to identify the amount of gold used, not to be confused with C, (carat), which refers to the weight of a gemstone. British usage calls for C to represent both protocols, and trouble often follows.

Gold Fineness
% of Gold Karat

   Karat weight of gold is important only to determine the true monetary value of a gold item, or to fulfill a particular personal or industrial requirement with respect to the other metals present in the alloy. As the karat level falls, the tarnishing factor rises, but is not noticeable above 14K.  12 or 10K gold will gain a tarnished look due to the abundance of the alloyed metals, but not from the gold itself.

100 24
91.7 22
75 18
58.3 14
41.6 10

Most gold alloys are called ternary, because most of them use 3 different metals to form the alloy. Most common is gold, silver and copper. Small amounts of other metals are added to create a specialty color, or to alter the working qualities of the metal, as in solder. Zinc, for example, is added to the mix to lower the melting temperature, or to lighten the gold color. In the US, 14K is the most common form of gold alloy, with 18K being more popular in Europe. 14 and 10K gold are most used when another color of gold is desired, such as red or green, but white gold is created by adding more silver and less copper. Occasionally, white gold is used to lower the cost of a jewelry piece instead of making it out of platinum, but it is very difficult to work with, and often breaks or disfigures during the working process. Sometimes, rhodium plating is used to create a satisfactory white gold surface, when price is not as much a factor. 18K gold shows great resistance to tarnishing, although 14K tarnishes within an acceptable range. Salts, including those excreted from the wearer’s body during perspiration, are mostly responsible for any sort of  tarnishing found, but it’s the silver and copper responsible for the discoloration, not the gold itself.

Gold Alloys (expressed in %)
Alloys / Elements Gold Silver Copper Zinc Cadmium Iron Aluminum Platinum Nickel
22K Yellow 91.67 5 2 1.33 0 0 0 0 0
18K Red 75 0 25 0 0 0 0 0 0
18K Rose 75 2.75 22.25 0 0 0 0 0 0
18K Pink 75 5 20 0 0 0 0 0 0
14K Yellow 58.33 8.3 29.2 4.17 0 0 0 0 0
18K Green 75 20 5 0 0 0 0 0 0
18K Deep Green 75 15 6 0 4 0 0 0 0
18K Blue 75 0 0 0 0 25 0 0 0
18K Purple 75 0 0 0 0 0 25 0 0
12K Red 50 0 50 0 0 0 0 0 0
12K Yellow 50 10 40 0 0 0 0 0 0
18K White 75 0 0 0 0 0 0 25 0
14K White 58.33 0 23.5 5.97 0 0 0 0 12.2
10K White 41.67 0 32.8 8.4 0 0 0 0 17.1


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Gold probably was found on the ground and used by prehistoric man as a tool. Highly sophisticated gold art objects and jewelry discovered by archaeologists in the Royal Tombs at Ur, in what is now Southern Iraq, date back to around 3000 BC. Similarly, goldsmiths of the Chavin civilization in Peru were making ornaments by hammering and embossing gold by 1200 BC. Gold attracted the attention of mankind everywhere and when it was found. Tracing some of the more important events in the existence of gold, and how it has affected our lives is a very interesting story.

In 4000 BC, Gold was first known to be used in parts of Central and Eastern Europe. By 3000 BC, Egyptians mastered the art of beating gold into gold leaf and alloying it with other metals. In 1500 BC, the Shekel, (two-thirds gold), was used as a standard unit of measure throughout the Middle East, and in 1091 BC, squares of gold were legalized in China as a form of money. It didn't take long to see the monetary value and use that gold possessed, and in 58 BC, Julius Caesar seized enough gold in Gaul, (France), to repay Rome's debts.

In 1100 AD, Venice secured its position as the world's leading gold bullion market due to it's location astride the trade routes to the east, so in 1511, King Ferdinand of Spain sent explorers to the Western Hemisphere with the command to "get gold". By 1717, gold was the monetary device for private commerce throughout the civilized world, with silver as a second. Isaac Newton, Master of the London Mint, set price of gold that lasted for the next 200 years.

In the United States, the first US gold coin was struck by Ephraim Brasher, a goldsmith, in 1787. In 1803, North Carolina was the site of the first US gold rush. That state supplied all the domestic gold coined for currency by the US Mint in Philadelphia until 1828. That changed in 1848, when the California gold rush began. James Marshall found specks of gold in the tailrace of John Sutter's sawmill near the junction of the American and Sacramento Rivers. The gold rush then spread to other parts of the world. In 1850, Edward Hammond Hargraves, returning from California, predicted he would find gold in Australia within one week. He discovered gold in New South Wales within one week of landing there. In 1886, George Harrison, (not that George Harrison, a different one), while digging stones to build a house, discovered gold in South Africa.

In 1887, Glasgow doctors, Robert and William Forrest, and chemist John S. MacArthur patented the process for extracting gold from ore using cyanide, but in 1896, two prospectors discovered gold while fishing in the Klondike River in northern Canada. Richer finds were rumored farther south in Alaska's Yukon, spawning the Alaska Gold Rush in 1898 -- the last gold rush of the century. Soon after, in 1900, the US adopted the gold standard for its currency. In 1903, the Engelhard Corporation introduced an organic medium to print gold on surfaces. First used for decoration, the medium became the foundation for microcircuit printing technology some years later.

In 1922, King Tutankhamen's tomb from 1352 BC, was opened to reveal a 2,448 lb. gold coffin and hundreds of gold and gold-leafed objects. Looting was immediately re-invented as a more lucrative avocation. In 1927, medical studies in France proved gold to be valuable in the  treatment of rheumatoid arthritis. Back in America, in 1933, President Franklin D. Roosevelt banned the export of gold, halted the convertibility of dollar bills into gold, and ordered US citizens to hand in all the gold they possessed and established a daily price for gold. Next year, in 1934, Roosevelt fixed the price of gold at $35 per ounce. In 1935, Western Electric Alloy #1 (69% gold, 25% silver and 6% platinum) found universal use in all switching contacts for AT&T telecommunications equipment, an application that would later be overtaken by pure silver. In 1947, the first transistor, the building block for electronics, was assembled at AT&T Bell Laboratories. The device used gold contacts pressed into a germanium surface.

In 1960, the laser was invented using gold-coated mirrors to maximize infrared reflection. Meanwhile, gold mining was continuing and growing in the western portion of the US. In 1961, modern-day mining began  in Nevada's Carlin Trend, ultimately making Nevada the nation's largest gold-mining state. More gold meant more research in the electronics field, and in 1968, Intel introduced a microchip with 1,024 transistors connected by gold circuits. On March 15 of that year, central banks gave up the fixed price of gold at $35 per troy ounce and let it free-float. The use of gold in technology continued to climb at a faster rate.

In 1969, gold coated visors protected astronauts' eyes from searing sunlight on the moon during the Apollo11 moon landing and has been used for the same purpose ever since. In 1970, the charged coupling device was invented, using gold to collect electrons generated by light, and was eventually used in hundreds of military and civilian devices, including video cameras. In 1971, the colloidal gold marker system was introduced by Amersham Corporation of Illinois. Tiny spheres of gold were used in health research laboratories worldwide to mark or tag specific proteins to reveal their function in the human body for the treatment of disease.

On December 31 1974, the US government ended its ban on individual ownership of gold. On January 21 1980, gold reached it's intra-day historic high price of $870 per ounce in New York. In 1986, gold-coated compact discs were introduced, but quickly replaced with silver-coated ones, only to be replaced with aluminum-coated discs after the discovery that silver coatings degraded over time. The electrical contact application continued to be a very important use for gold, however. In 1987, airbags were  introduced for cars, using gold contacts for reliability. In 1996, the Mars Global Surveyor launched with an on-board gold-coated parabolic telescope-mirror that generated a detailed map of the entire Martian surface over a two-year period.

In 1997 Congress passed the  Taxpayers Relief Act, allowing US Individual Retirement Account holders to buy gold bullion coins and bars for their accounts as long as they are of a fineness equal to or exceeding  99.5% gold.

Sources: The Gold Institute,   Jewelry Concepts and Technology, Untract, 1982, Peter L Bernstein.