The three most popular precious metals are gold, silver, and platinum. These metals are used alone or alloyed with other metals to make jewelry and coins in addition to their industrial uses.
Gold has the longest history of use in jewelry of all precious metals. Gold is very scarce and it takes approximately 3.2 tones of mining ore to produce 1 ounce of pure gold. Gold is a very strong metal but also very malleable so it is frequently alloyed with other metals to increase its strength, durability, and color. The most common colors of gold used in jewelry are yellow gold, white gold, and rose gold. The fineness of gold is measured in karats which denotes how many parts pure gold out of 24 parts. Pure gold is 24 karat and is rarely used in jewelry as it is too soft. The most commonly available gold bullion coins are 22 or 24 karat gold. All jewelry sold in the United States must be a minimum of 10 karat gold and stamped somewhere on the jewelry. Below is a breakdown of gold karat content and purity:
Platinum is the rarest of the precious metals commonly used in jewelry. Only about 150 tons are produced a year compared to 1500 tons of gold. It takes approximately 10 tons of mining ore to produce 1 ounce of platinum. Platinum has a relatively short history of use in jewelry due to the difficultness of working with it. Platinum is very heavy and durable, as well as hypoallergenic and tarnish resistant. Naturally white, platinum jewelry is 90-95% pure while platinum bullion is usually 99.9% pure. Platinum jewelry will have stamps indicating its purity.
Silver is the most widely used precious metal of the precious metals commonly used in jewelry. According to estimates, there are approximately 17 ounces of silver for every ounce of gold. In ancient Egypt, silver was considered more valuable then gold and the leading producing countries in the world today are Peru and Mexico.
Sterling Silver jewelry is the United States is made up of 92.5 % silver mixed with other metals and will be stamped ".925" or "sterling". Most silver flatware is made of sterling silver although lower quality silver was also used in flatware.
More than 95% of annual silver consumption is from industrial and decorative uses: photography, jewelry, and silverware.